diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,15 +1,27 @@
 # Revision history for glirc2
 
+## 2.28
+* Add formatting reference to `/palette`
+* Make RTLD flags configurable when loading an extension
+* Update client's internal hostname on `RPL_HOSTHIDDEN`
+* Support IRCv3.2 `server-time` extension over ZNC-specific one
+* Lots of work on the Lua extension code and documentation
+* Added `glirc_user_account` and `glirc_user_channel_modes`
+  extension API entrypoints.
+* Added support for `account-notify` and `extended-join`
+* Added configurable "arguments" to the C extensions
+
 ## 2.27
 * Requires GHC 8.4
 * Show channel topic in channel on join
 * Fix socket leak when failing to load TLS certificates
 * Add delay when indicating sent ping to reduce noise
+* Add support for italics in formatting
 
 ## 2.26
 * Updates for GHC 8.4.1
 * Added `/toggle-show-ping` and `show-ping` configuration setting
-  to toggle visibility of the ping roundtrip times.
+  to toggle visibility of the ping round-trip times.
 
 ## 2.25
 * `/ignore` can list ignores and supports full wildcard masks
@@ -30,9 +42,9 @@
   for the home directory works for resolving paths relative
   to $HOME. Absolute paths are unmodified.
 
-* Support network:#channel in /query
+* Support `network:#channel` in `/query`
 
-* Add an optional OTR extension. See the otr-extension/ directory
+* Add an optional OTR extension. See the `otr-extension/` directory
   and the wiki for more information.
 
 * Extended the C API with `glirc_inject_chat` and `chat_entrypoint`
@@ -46,7 +58,7 @@
 
 ## 2.22
 
-* Added dynanic indentation of wrapped lines. Lines now
+* Added dynamic indentation of wrapped lines. Lines now
   wrap to where the message portion of the line started.
   This removes `indent-wrapped-lines` configuration setting
 * Added pervasive word-boundary oriented line wrapping
@@ -59,21 +71,21 @@
 * Memory savings by packing message timestamp information, and
   using the "detailed" image for regular expression matching.
 * Added `/rtsstats` command for inspecting the GHC RTS statistics
-* Added many minor IRC query commands: admin, info, map, rules
-  motd, version, lusers, kill, knock, list.
+* Added many minor IRC query commands: `admin`, `info`, `map`, `rules`
+  `motd`, `version`, `lusers`, `kill`, `knock`, `list`.
 
 ## 2.21.1
 
-* Support for latest config-schema
+* Support for latest `config-schema`
 * Adapt extension API to help support stub Rust extension
 
 ## 2.21
 
-* Make metadata toggle (F4) a window-level setting instead of client level
+* Make metadata toggle `F4` a window-level setting instead of client level
 * Add configuration option to hide metadata by default `hide-metadata`
 * Make keymap configurable under `key-bindings`, add `/keymap` command
-* Add transient error message view, press ESC to clear
-* Implement two-column split window mode: `/toggle-layout` and F5
+* Add transient error message view, press `ESC` to clear
+* Implement two-column split window mode: `/toggle-layout` and `F5`
 * Implement word-boundary based line wrapping
 
 ## 2.20.6
@@ -138,10 +150,10 @@
 ## 2.17
 
 * Add `reconnect-attempts` setting
-* Add peristence for `/grep` and `/grepi`
+* Add persistence for `/grep` and `/grepi`
 * Add filter argument to `/windows`
 * Better tab completion for `/channel` and `/focus`
-* Isolate and number urls in view with `/url`
+* Isolate and number URLs in view with `/url`
 * Map `M-Left` and `M-Right` to backward word and forward word
 
 ## 2.16
@@ -154,8 +166,8 @@
 * Add macro argument declarations
 * Add indication when a command is still a prefix or not of a valid command
 * Support quoted strings arguments to /exec
-* Add F4 to toggle visibility of metadata lines
-* tls-insecure setting was incorrectly behaving like normal insecure
+* Add `F4` to toggle visibility of metadata lines
+* `tls-insecure` setting was incorrectly behaving like normal insecure
 * Add `C-t` to swap characters
 * Add `ESC` to return to messages window
 
@@ -163,11 +175,11 @@
 
 * Add `/help`
 * Add `/palette`
-* Add F3 to toggle activity detail bar
+* Add `F3` to toggle activity detail bar
 
 ## 2.13
 
-* Add disconnect expansion, support expansions in connect-cmds
+* Add disconnect expansion, support expansions in `connect-cmds`
 * Add default expansion syntax `${var|default}`
 * Add support for multiple nicknames to try on connect
 * Add `ignores` section to configuration
@@ -184,7 +196,7 @@
 
 * Add `M-S` to jump to previously focused window
 * Add `extra-highlights` section
-* Tab complete servernames in `/connect`
+* Tab complete server names in `/connect`
 * Add `/windows` command for listing active windows
 * Add `glirc_clear_window` C API procedure
 * Allow `process_message` callback to drop messages
@@ -194,7 +206,7 @@
 
 ## 2.10
 
-* Fixes for multiline editing
+* Fixes for multi-line editing
 * Multiple, sequential kills all fill the same yank buffer
 
 ## 2.9
@@ -207,12 +219,12 @@
 ## 2.8
 
 * Support `vty-5.8`
-* Implement inital support for macros
+* Implement initial support for macros
 * Support `znc.in/self-message`
 
 ## 2.7
 
-* Switch to regex-tdfa (easier to install on macOS than text-icu)
+* Switch to `regex-tdfa` (easier to install on MacOS than `text-icu`)
 * Tab-complete starts with most recent nick
 * Add `/reload`
 * Add custom palette entry for self highlights
@@ -220,17 +232,17 @@
 
 ## 2.6
 
-* connect-cmds now use actual client commands instead of raw IRC messages. For example `msg user my message` or `join #mychannel`
-* Multiple lines can be held in the textbox at once. Pasting mutiple lines insert those lines into the textbox rather than sending them immediately.
+* `connect-cmds` now use actual client commands instead of raw IRC messages. For example `msg user my message` or `join #mychannel`
+* Multiple lines can be held in the textbox at once. Pasting multiple lines insert those lines into the textbox rather than sending them immediately.
 * Added `M-d` and `M-Enter` key bindings
 * Added `name` field to server configuration
-* Extract irc-core library again
+* Extract `irc-core` library again
 * Configurable self color
 
 ## 2.5
 
-* Add facilities for hooks that can alter the irc message stream.
-* Implement a hook that handles the znc buffextras plugin.
+* Add facilities for hooks that can alter the IRC message stream.
+* Implement a hook that handles the ZNC `buffextras` plugin.
 * Implement configurable nick color highlight palette.
 * Resolve relative paths starting at the home directory.
 * Significantly configurable UI colors
@@ -246,7 +258,7 @@
 
 * Add commands `/znc`
 * Add initial support for ZNC's playback module and `/znc-playback` command
-* Don't consider message seen when in masklist, userlist, or channelinfo windows
+* Don't consider message seen when in `masklist`, `userlist`, or `channelinfo` windows
 * Add terminal bell on command error
 
 ## 2.2
diff --git a/exec/Exports.hs b/exec/Exports.hs
--- a/exec/Exports.hs
+++ b/exec/Exports.hs
@@ -6,6 +6,7 @@
 Maintainer  : emertens@gmail.com
 
 Entry point into glirc2 from the C API
+
 -}
 module Exports () where
 
@@ -19,12 +20,15 @@
 foreign export ccall glirc_list_networks      :: Glirc_list_networks
 foreign export ccall glirc_identifier_cmp     :: Glirc_identifier_cmp
 foreign export ccall glirc_is_channel         :: Glirc_is_channel
-foreign export ccall glirc_is_logged_on       :: Glirc_is_channel
+foreign export ccall glirc_is_logged_on       :: Glirc_is_logged_on
 foreign export ccall glirc_list_channels      :: Glirc_list_channels
 foreign export ccall glirc_list_channel_users :: Glirc_list_channel_users
 foreign export ccall glirc_my_nick            :: Glirc_my_nick
+foreign export ccall glirc_user_account       :: Glirc_user_account
+foreign export ccall glirc_user_channel_modes :: Glirc_user_channel_modes
 foreign export ccall glirc_mark_seen          :: Glirc_mark_seen
 foreign export ccall glirc_clear_window       :: Glirc_clear_window
 foreign export ccall glirc_free_string        :: Glirc_free_string
 foreign export ccall glirc_free_strings       :: Glirc_free_strings
 foreign export ccall glirc_current_focus      :: Glirc_current_focus
+foreign export ccall glirc_resolve_path       :: Glirc_resolve_path
diff --git a/exec/Main.hs b/exec/Main.hs
--- a/exec/Main.hs
+++ b/exec/Main.hs
@@ -30,8 +30,8 @@
 main =
   do opts <- getOptions
      let mbPath = view optConfigFile opts
-     cfg  <- loadConfiguration' mbPath
-     withClientState mbPath cfg $ \st0 ->
+     (path,cfg) <- loadConfiguration' mbPath
+     withClientState path cfg $ \st0 ->
        withVty $ \vty ->
          do st1 <- clientStartExtensions    st0
             st2 <- initialNetworkLogic opts st1
@@ -46,11 +46,11 @@
       | otherwise              = view optInitialNetworks opts ++ clientAutoconnects st
 
 -- | Load configuration and handle errors along the way.
-loadConfiguration' :: Maybe FilePath -> IO Configuration
-loadConfiguration' path =
-  do cfgRes <- loadConfiguration path
+loadConfiguration' :: Maybe FilePath -> IO (FilePath, Configuration)
+loadConfiguration' mbPath =
+  do cfgRes <- loadConfiguration mbPath
      case cfgRes of
-       Right cfg -> return cfg
+       Right x -> return x
        Left (ConfigurationReadFailed e) ->
          report "Failed to open configuration:" e
        Left (ConfigurationParseFailed p e) ->
diff --git a/exec/linux_exported_symbols.txt b/exec/linux_exported_symbols.txt
--- a/exec/linux_exported_symbols.txt
+++ b/exec/linux_exported_symbols.txt
@@ -7,11 +7,14 @@
 glirc_list_channels;
 glirc_list_channel_users;
 glirc_my_nick;
+glirc_user_account;
+glirc_user_channel_modes;
 glirc_mark_seen;
 glirc_is_channel;
 glirc_is_logged_on;
 glirc_clear_window;
 glirc_current_focus;
+glirc_resolve_path;
 glirc_free_string;
 glirc_free_strings;
 };
diff --git a/exec/macos_exported_symbols.txt b/exec/macos_exported_symbols.txt
--- a/exec/macos_exported_symbols.txt
+++ b/exec/macos_exported_symbols.txt
@@ -6,10 +6,13 @@
 _glirc_list_channels
 _glirc_list_channel_users
 _glirc_my_nick
+_glirc_user_account
+_glirc_user_channel_modes
 _glirc_mark_seen
 _glirc_is_channel
 _glirc_is_logged_on
 _glirc_clear_window
 _glirc_current_focus
+_glirc_resolve_path
 _glirc_free_string
 _glirc_free_strings
diff --git a/glirc.cabal b/glirc.cabal
--- a/glirc.cabal
+++ b/glirc.cabal
@@ -1,5 +1,6 @@
+cabal-version:       2.2
 name:                glirc
-version:             2.27
+version:             2.28
 synopsis:            Console IRC client
 description:         Console IRC client
                      .
@@ -13,19 +14,17 @@
 maintainer:          emertens@gmail.com
 copyright:           2016,2017 Eric Mertens
 category:            Network
-build-type:          Custom
 extra-source-files:  ChangeLog.md README.md
                      exec/linux_exported_symbols.txt
                      exec/macos_exported_symbols.txt
-cabal-version:       >=1.23
 homepage:            https://github.com/glguy/irc-core
 bug-reports:         https://github.com/glguy/irc-core/issues
-tested-with:         GHC==8.0.2
+tested-with:         GHC==8.4.3
 
 custom-setup
   setup-depends: base     >=4.11 && <4.12,
                  filepath >=1.4  && <1.5,
-                 Cabal    >=1.24 && <2.3
+                 Cabal    >=2.2  && <2.3,
 
 source-repository head
   type: git
@@ -124,6 +123,9 @@
                        Paths_glirc
                        Build_glirc
 
+  autogen-modules:     Paths_glirc
+                       Build_glirc
+
   build-depends:       base                 >=4.11   && <4.12,
                        HsOpenSSL            >=0.11   && <0.12,
                        async                >=2.1    && <2.3,
@@ -139,7 +141,7 @@
                        gitrev               >=1.2    && <1.4,
                        hashable             >=1.2.4  && <1.3,
                        hookup               >=0.2.2  && <0.3,
-                       irc-core             >=2.3    && <2.4,
+                       irc-core             >=2.5    && <2.6,
                        kan-extensions       >=5.0    && <5.3,
                        lens                 >=4.14   && <4.18,
                        network              >=2.6.2  && <2.8,
@@ -155,7 +157,7 @@
                        unix                 >=2.7    && <2.8,
                        unordered-containers >=0.2.7  && <0.3,
                        vector               >=0.11   && <0.13,
-                       vty                  >=5.23.1 && <5.24
+                       vty                  >=5.23.1 && <5.24,
 
 test-suite test
   type:                exitcode-stdio-1.0
diff --git a/include/glirc-api.h b/include/glirc-api.h
--- a/include/glirc-api.h
+++ b/include/glirc-api.h
@@ -43,7 +43,7 @@
         struct glirc_string command;
 };
 
-typedef void *start_type         (struct glirc *G, const char *path);
+typedef void *start_type         (struct glirc *G, const char *path, const struct glirc_string *args, size_t args_len);
 typedef void stop_type           (struct glirc *G, void *S);
 typedef enum process_result process_message_type(struct glirc *G, void *S, const struct glirc_message *);
 typedef enum process_result process_chat_type(struct glirc *G, void *S, const struct glirc_chat *);
@@ -67,17 +67,20 @@
                 const char* tgt, size_t tgtLen,
                 const char* msg, size_t msgLen);
 char ** glirc_list_networks(struct glirc *G);
-char ** glirc_list_channels(struct glirc *G, struct glirc_string network);
-char ** glirc_list_channel_users(struct glirc *G, struct glirc_string network, struct glirc_string channel);
+char ** glirc_list_channels(struct glirc *G, const char *net, size_t netlen);
+char ** glirc_list_channel_users(struct glirc *G, const char *net, size_t net_len, const char *chan, size_t chan_len);
 void glirc_current_focus(struct glirc *G, char **net, size_t *netlen, char **tgt , size_t *tgtlen);
 char * glirc_my_nick(struct glirc *G, const char *net, size_t netlen);
-void glirc_mark_seen(struct glirc *G, struct glirc_string network, struct glirc_string channel);
-void glirc_clear_window(struct glirc *G, struct glirc_string network, struct glirc_string channel);
-int glirc_identifier_cmp(struct glirc_string s, struct glirc_string t);
+char * glirc_user_account(struct glirc *G, const char *net, size_t netlen, const char *nick, size_t nicklen);
+char * glirc_user_channel_modes(struct glirc *G, const char *net, size_t netlen, const char *chan, size_t chanlen, const char *nick, size_t nicklen);
+void glirc_mark_seen(struct glirc *G, const char *net, size_t net_len, const char *chan, size_t chan_len);
+void glirc_clear_window(struct glirc *G, const char *net, size_t net_len, const char *chan, size_t chan_len);
+int glirc_identifier_cmp(const char *s, size_t s_len, const char *t, size_t t_len);
 int glirc_is_channel(struct glirc *G, const char *net, size_t netlen,
                                       const char *tgt, size_t tgtlen);
 int glirc_is_logged_on(struct glirc *G, const char *net, size_t netlen,
                                         const char *tgt, size_t tgtlen);
+char * glirc_resolve_path(struct glirc *G, const char *path, size_t path_len);
 
 void glirc_free_string(char *);
 void glirc_free_strings(char **);
diff --git a/src/Client/CApi.hs b/src/Client/CApi.hs
--- a/src/Client/CApi.hs
+++ b/src/Client/CApi.hs
@@ -24,7 +24,11 @@
   , chatExtension
   ) where
 
+import           Client.Configuration
+                   (ExtensionConfiguration,
+                    extensionPath, extensionRtldFlags, extensionArgs)
 import           Client.CApi.Types
+import           Control.Lens (view)
 import           Control.Monad
 import           Control.Monad.IO.Class
 import           Control.Monad.Codensity
@@ -67,17 +71,24 @@
 -- passed to any subsequent calls into the extension.
 activateExtension ::
   Ptr () ->
-  FilePath {- ^ path to extension -} ->
+  ExtensionConfiguration {- ^ extension configuration -} ->
   IO ActiveExtension
-activateExtension stab path =
-  do dl   <- dlopen path [RTLD_NOW, RTLD_LOCAL]
+activateExtension stab config =
+  do dl   <- dlopen (view extensionPath config)
+                    (view extensionRtldFlags config)
      p    <- dlsym dl extensionSymbol
      fgn  <- peek (castFunPtrToPtr p)
      name <- peekCString (fgnName fgn)
      let f = fgnStart fgn
      s  <- if nullFunPtr == f
              then return nullPtr
-             else withCString path (runStartExtension f stab)
+             else evalNestedIO $
+                  do extPath <- nest1 (withCString (view extensionPath config))
+                     args <- traverse withText
+                           $ view extensionArgs config
+                     argsArray <- nest1 (withArray args)
+                     let len = fromIntegral (length args)
+                     liftIO (runStartExtension f stab extPath argsArray len)
      return $! ActiveExtension
        { aeFgn     = fgn
        , aeDL      = dl
diff --git a/src/Client/CApi/Exports.hs b/src/Client/CApi/Exports.hs
--- a/src/Client/CApi/Exports.hs
+++ b/src/Client/CApi/Exports.hs
@@ -8,9 +8,11 @@
 
 This module exports the C functions that extensions can used to query the state
 of the client.
+
+C Extensions can include @glirc-api.h@
 -}
 module Client.CApi.Exports
- ( -- * Extension API types
+ ( -- * Extension entry-points
    Glirc_send_message
  , glirc_send_message
 
@@ -29,6 +31,12 @@
  , Glirc_my_nick
  , glirc_my_nick
 
+ , Glirc_user_account
+ , glirc_user_account
+
+ , Glirc_user_channel_modes
+ , glirc_user_channel_modes
+
  , Glirc_identifier_cmp
  , glirc_identifier_cmp
 
@@ -55,9 +63,14 @@
 
  , Glirc_inject_chat
  , glirc_inject_chat
+
+ , Glirc_resolve_path
+ , glirc_resolve_path
+
  ) where
 
 import           Client.CApi.Types
+import           Client.Configuration
 import           Client.Message
 import           Client.State
 import           Client.State.Channel
@@ -126,12 +139,14 @@
 
 ------------------------------------------------------------------------
 
--- | Network, command, and parameters are used when transmitting a message.
+-- | Type of 'glirc_send_message' extension entry-point
 type Glirc_send_message =
   Ptr ()     {- ^ api token          -} ->
   Ptr FgnMsg {- ^ pointer to message -} ->
   IO CInt    {- ^ 0 on success       -}
 
+-- | Entry-point into the client when an extern extension wants send an IRC
+-- command to a connected server.
 glirc_send_message :: Glirc_send_message
 glirc_send_message token msgPtr =
   do mvar    <- derefToken token
@@ -147,14 +162,17 @@
 
 ------------------------------------------------------------------------
 
--- | Print a message or error to the client window
+-- | Type of 'glirc_print' extension entry-point
 type Glirc_print =
-  Ptr ()  {- ^ api token         -} ->
+  Ptr ()      {- ^ api token         -} ->
   MessageCode {- ^ enum message_code -} ->
-  CString {- ^ message           -} ->
-  CSize   {- ^ message length    -} ->
-  IO CInt {- ^ 0 on success      -}
+  CString     {- ^ message           -} ->
+  CSize       {- ^ message length    -} ->
+  IO CInt     {- ^ 0 on success      -}
 
+-- | Entry-point for extensions to append a message to the client buffer.
+-- The @message_code@ can be used to render the message normally or to
+-- cause the client to draw attention to the message as an error.
 glirc_print :: Glirc_print
 glirc_print stab code msgPtr msgLen =
   do mvar <- derefToken stab
@@ -175,7 +193,7 @@
 
 ------------------------------------------------------------------------
 
--- | Print a message or error to the client window
+-- | Type of 'glirc_inject_chat' extension entry-point.
 type Glirc_inject_chat =
   Ptr ()  {- ^ api token         -} ->
   CString {- ^ network           -} ->
@@ -188,6 +206,10 @@
   CSize   {- ^ message length    -} ->
   IO CInt {- ^ 0 on success      -}
 
+-- | Add a message to a chat window as if it was received
+-- directly from the IRC server. This is useful when implementing
+-- extensions that intercept incoming chat messages and transform
+-- them before showing the user.
 glirc_inject_chat :: Glirc_inject_chat
 glirc_inject_chat stab netPtr netLen srcPtr srcLen tgtPtr tgtLen msgPtr msgLen =
   do mvar <- derefToken stab
@@ -209,12 +231,15 @@
 
 ------------------------------------------------------------------------
 
--- | The resulting strings and array of strings are malloc'd and the
--- caller must free them. NULL returned on failure.
+-- | Type of 'glirc_list_networks' extension entry-point
 type Glirc_list_networks =
   Ptr ()           {- ^ api token                                        -} ->
   IO (Ptr CString) {- ^ null terminated array of null terminated strings -}
 
+-- | This extension entry-point allocates a list of all the identifiers for
+-- the active networks on the client. @NULL@ returned on failure.
+-- The caller is responsible for freeing successful result with
+-- @glirc_free_strings@.
 glirc_list_networks :: Glirc_list_networks
 glirc_list_networks stab =
   do mvar <- derefToken stab
@@ -225,10 +250,7 @@
 
 ------------------------------------------------------------------------
 
--- | Case insensitive comparison suitable for use on channels and nicknames.
--- Returns -1 if the first identifier is less than the second
--- Returns 0 if the first identifier is equal to the second
--- Returns 1 if the first identifier is greater than the second
+-- | Type of 'glirc_identifier_cmp' extension entry-point
 type Glirc_identifier_cmp =
   CString {- ^ identifier 1     -} ->
   CSize   {- ^ identifier 1 len -} ->
@@ -236,6 +258,10 @@
   CSize   {- ^ identifier 2 len -} ->
   IO CInt
 
+-- | Case insensitive comparison suitable for use on channels and nicknames.
+-- Returns -1 if the first identifier is less than the second
+-- Returns 0 if the first identifier is equal to the second
+-- Returns 1 if the first identifier is greater than the second
 glirc_identifier_cmp :: Glirc_identifier_cmp
 glirc_identifier_cmp p1 n1 p2 n2 =
   do txt1 <- peekFgnStringLen (FgnStringLen p1 n1)
@@ -247,14 +273,16 @@
 
 ------------------------------------------------------------------------
 
--- | The resulting strings and array of strings are malloc'd and the
--- caller must free them. NULL returned on failure.
+-- | Type of 'glirc_list_channels' extension entry-point
 type Glirc_list_channels =
   Ptr ()  {- ^ api token   -} ->
   CString {- ^ network     -} ->
   CSize   {- ^ network len -} ->
   IO (Ptr CString) {- ^ null terminated array of null terminated strings -}
 
+-- | Generate a list of connected channels for the network identified in
+-- the arguments. @NULL@ returned on failure. Caller is responsible for
+-- freeing successful result with @glirc_free_strings@.
 glirc_list_channels :: Glirc_list_channels
 glirc_list_channels stab networkPtr networkLen =
   do mvar <- derefToken stab
@@ -268,8 +296,7 @@
 
 ------------------------------------------------------------------------
 
--- | The resulting strings and array of strings are malloc'd and the
--- caller must free them.  NULL returned on failure.
+-- | Type of 'glirc_list_channel_users' extension entry-point
 type Glirc_list_channel_users =
   Ptr ()  {- ^ api token   -} ->
   CString {- ^ network     -} ->
@@ -278,6 +305,10 @@
   CSize   {- ^ channel len -} ->
   IO (Ptr CString) {- ^ null terminated array of null terminated strings -}
 
+-- | Generate a list of IRC nicknames currently connected to the identified
+-- channel on the identified network. @NULL@ returned on failure.
+-- Caller is responsible for freeing successful result with
+-- @glirc_free_strings@.
 glirc_list_channel_users :: Glirc_list_channel_users
 glirc_list_channel_users stab networkPtr networkLen channelPtr channelLen =
   do mvar <- derefToken stab
@@ -296,14 +327,17 @@
 
 ------------------------------------------------------------------------
 
--- | The resulting string is malloc'd and the caller must free it.
--- NULL returned on failure.
+-- | Type of 'glirc_my_nick' extension entry-point
 type Glirc_my_nick =
   Ptr ()  {- ^ api token           -} ->
   CString {- ^ network name        -} ->
   CSize   {- ^ network name length -} ->
   IO CString
 
+-- | Return the IRC nickname associated with the active network
+-- connection identified in the arguments. @NULL@ returned on failure.
+-- Caller is responsible for freeing successful result with
+-- @glirc_free_string@.
 glirc_my_nick :: Glirc_my_nick
 glirc_my_nick stab networkPtr networkLen =
   do mvar <- derefToken stab
@@ -316,9 +350,66 @@
 
 ------------------------------------------------------------------------
 
--- | Mark a window as being seen clearing the new message counter.
--- To clear the client window send an empty network name.
--- To clear a network window send an empty channel name.
+-- | Type of 'glirc_user_account' extension entry-point
+type Glirc_user_account =
+  Ptr ()  {- ^ api token           -} ->
+  CString {- ^ network name        -} ->
+  CSize   {- ^ network name length -} ->
+  CString {- ^ nickname            -} ->
+  CSize   {- ^ nickname length     -} ->
+  IO CString
+
+-- | Return the services account name associated with a nickname on
+-- a server as tracked by the client. Caller is responsible for freeing
+-- successful result with @glirc_free_string@. If no account is
+-- known, @NULL@ is returned.
+glirc_user_account :: Glirc_user_account
+glirc_user_account stab networkPtr networkLen nickPtr nickLen =
+  do mvar    <- derefToken stab
+     st      <- readMVar mvar
+     network <- peekFgnStringLen (FgnStringLen networkPtr networkLen)
+     nick    <- peekFgnStringLen (FgnStringLen nickPtr    nickLen   )
+     let mb = preview ( clientConnection network
+                      . csUsers . ix (mkId nick)
+                      . uhAccount . filtered (not . Text.null)) st
+     case mb of
+       Just acct -> newCString (Text.unpack acct)
+       _         -> return nullPtr
+
+------------------------------------------------------------------------
+
+-- | Type of 'glirc_user_account' extension entry-point
+type Glirc_user_channel_modes =
+  Ptr ()  {- ^ api token           -} ->
+  CString {- ^ network name        -} ->
+  CSize   {- ^ network name length -} ->
+  CString {- ^ channel             -} ->
+  CSize   {- ^ channel length      -} ->
+  CString {- ^ nickname            -} ->
+  CSize   {- ^ nickname length     -} ->
+  IO CString
+
+-- | Return the sigils associated with a nickname on a particular channel.
+-- Caller is responsible for freeing successful result with
+-- @glirc_free_string@. If user is on channel without any sigils an empty
+-- string is returned. If user is not on channel @NULL@ is returned.
+glirc_user_channel_modes :: Glirc_user_channel_modes
+glirc_user_channel_modes stab netPtr netLen chanPtr chanLen nickPtr nickLen =
+  do mvar    <- derefToken stab
+     st      <- readMVar mvar
+     network <- peekFgnStringLen (FgnStringLen netPtr  netLen)
+     chan    <- peekFgnStringLen (FgnStringLen chanPtr chanLen   )
+     nick    <- peekFgnStringLen (FgnStringLen nickPtr nickLen   )
+     let mb = preview ( clientConnection network
+                      . csChannels . ix (mkId chan)
+                      . chanUsers  . ix (mkId nick) ) st
+     case mb of
+       Just sigils -> newCString sigils
+       Nothing     -> return nullPtr
+
+------------------------------------------------------------------------
+
+-- | Type of 'glirc_mark_seen' extension entry-point
 type Glirc_mark_seen =
   Ptr ()  {- ^ api token           -} ->
   CString {- ^ network name        -} ->
@@ -327,6 +418,9 @@
   CSize   {- ^ channel name length -} ->
   IO ()
 
+-- | Mark a window as being seen, clearing the new message counter.
+-- To specify the client window send an empty network name.
+-- To specify a network window send an empty channel name.
 glirc_mark_seen :: Glirc_mark_seen
 glirc_mark_seen stab networkPtr networkLen channelPtr channelLen =
   do network <- peekFgnStringLen (FgnStringLen networkPtr networkLen)
@@ -343,9 +437,7 @@
 
 ------------------------------------------------------------------------
 
--- | Mark a window as being seen clearing the new message counter.
--- To clear the client window send an empty network name.
--- To clear a network window send an empty channel name.
+-- | Type of 'glirc_clear_window' extension entry-point
 type Glirc_clear_window =
   Ptr ()  {- ^ api token           -} ->
   CString {- ^ network name        -} ->
@@ -354,6 +446,9 @@
   CSize   {- ^ channel name length -} ->
   IO ()
 
+-- | Clear contents of a specified window.
+-- To specify the client window send an empty network name.
+-- To specify a network window send an empty channel name.
 glirc_clear_window :: Glirc_clear_window
 glirc_clear_window stab networkPtr networkLen channelPtr channelLen =
   do network <- peekFgnStringLen (FgnStringLen networkPtr networkLen)
@@ -370,23 +465,25 @@
 
 ------------------------------------------------------------------------
 
--- | Free one of the heap allocated strings found as a return value
--- from the extension API. If argument is NULL, nothing happens.
+-- | Type of 'glirc_free_string' extension entry-point
 type Glirc_free_string =
   CString {- ^ glirc allocated string -} ->
   IO ()
 
+-- | Free one of the heap allocated strings found as a return value
+-- from the extension API. If argument is @NULL@, nothing happens.
 glirc_free_string :: Glirc_free_string
 glirc_free_string = free
 
 ------------------------------------------------------------------------
 
--- | Free an array of heap allocated strings found as a return value
--- from the extension API. If argument is NULL, nothing happens.
+-- | Type of 'glirc_free_strings' extension entry-point
 type Glirc_free_strings =
   Ptr CString {- ^ glirc allocated strings, null-terminated -} ->
   IO ()
 
+-- | Free an array of heap allocated strings found as a return value
+-- from the extension API. If argument is @NULL@, nothing happens.
 glirc_free_strings :: Glirc_free_strings
 glirc_free_strings p =
   unless (p == nullPtr) $
@@ -395,13 +492,7 @@
 
 ------------------------------------------------------------------------
 
--- | Free an array of heap allocated strings found as a return value
--- from the extension API. If argument is NULL, nothing happens.
---
--- Free the allocated strings with @glirc_free_string@
---
--- Strings set to NULL if there is no current network or no
--- current target.
+-- | Type of 'glirc_current_focus' extension entry-point
 type Glirc_current_focus =
   Ptr ()      {- ^ api token                      -} ->
   Ptr CString {- ^ newly allocated network string -} ->
@@ -410,29 +501,27 @@
   Ptr CSize   {- ^ target length                  -} ->
   IO ()
 
+-- | Find the network and target identifier associated with the
+-- currently focused window.
+--
+-- Free the allocated strings with @glirc_free_string@.
+--
+-- Strings set to @NULL@ if there is no current network or no
+-- current target.
 glirc_current_focus :: Glirc_current_focus
 glirc_current_focus stab netP netL tgtP tgtL =
   do mvar <- derefToken stab
      st   <- readMVar mvar
-     case view clientFocus st of
-       Unfocused        -> do poke' netP nullPtr
-                              poke' netL 0
-                              poke' tgtP nullPtr
-                              poke' tgtL 0
-
-       NetworkFocus n   -> do exportText netP netL n
-                              poke' tgtP nullPtr
-                              poke' tgtL 0
-
-       ChannelFocus n t -> do exportText netP netL n
-                              exportText tgtP tgtL (idText t)
+     let (net,tgt) = case view clientFocus st of
+                       Unfocused        -> (Text.empty, Text.empty)
+                       NetworkFocus n   -> (n         , Text.empty)
+                       ChannelFocus n t -> (n         , idText t  )
+     exportText netP netL net
+     exportText tgtP tgtL tgt
 
 ------------------------------------------------------------------------
 
--- | Returns @1@ when the given target on the given network is a channel
--- name, otherwise returns @0@.
---
--- If the given network is not currently active this returns @0@.
+-- | Type of 'glirc_is_channel' extension entry-point
 type Glirc_is_channel =
   Ptr ()  {- ^ api token       -} ->
   CString {- ^ network name    -} ->
@@ -441,6 +530,10 @@
   CSize   {- ^ target length   -} ->
   IO CInt {- ^ boolean         -}
 
+-- | Returns @1@ when the given target on the given network is a channel
+-- name, otherwise returns @0@.
+--
+-- If the given network is not currently active this returns @0@.
 glirc_is_channel :: Glirc_is_channel
 glirc_is_channel stab net netL tgt tgtL =
   do mvar    <- derefToken stab
@@ -454,10 +547,7 @@
 
 ------------------------------------------------------------------------
 
--- | Returns @1@ when the given target on the given network shares a
--- channel with the user, @0@ otherwise.
---
--- If the given network is not currently active this returns @0@.
+-- | Type of 'glirc_is_logged_on' extension entry-point
 type Glirc_is_logged_on =
   Ptr ()  {- ^ api token       -} ->
   CString {- ^ network name    -} ->
@@ -466,7 +556,11 @@
   CSize   {- ^ target length   -} ->
   IO CInt {- ^ boolean         -}
 
-glirc_is_logged_on :: Glirc_is_channel
+-- | Returns @1@ when the given target on the given network shares a
+-- channel with the user, @0@ otherwise.
+--
+-- If the given network is not currently active this returns @0@.
+glirc_is_logged_on :: Glirc_is_logged_on
 glirc_is_logged_on stab net netL tgt tgtL =
   do mvar    <- derefToken stab
      st      <- readMVar mvar
@@ -475,3 +569,27 @@
 
      let online = has (clientConnection network . csUsers . ix (mkId target)) st
      return $! if online then 1 else 0
+
+------------------------------------------------------------------------
+
+-- | Type of 'glirc_resolve_path' extension entry-point
+type Glirc_resolve_path =
+  Ptr ()     {- ^ api token     -} ->
+  CString    {- ^ path          -} ->
+  CSize      {- ^ path length   -} ->
+  IO CString {- ^ resolved path -}
+
+-- | Resolve the given string to an absolute path. This expands @~@ for
+-- the home directory and computes paths relative to the configuration
+-- file.
+--
+-- Free the allocated string with @glirc_free_string@.
+glirc_resolve_path :: Glirc_resolve_path
+glirc_resolve_path stab pathP pathL =
+  do mvar    <- derefToken stab
+     st      <- readMVar mvar
+     path    <- peekFgnStringLen (FgnStringLen pathP pathL)
+
+     let cfgPath = view clientConfigPath st
+     cxt <- newFilePathContext cfgPath
+     newCString (resolveFilePath cxt (Text.unpack path))
diff --git a/src/Client/CApi/Types.hsc b/src/Client/CApi/Types.hsc
--- a/src/Client/CApi/Types.hsc
+++ b/src/Client/CApi/Types.hsc
@@ -20,6 +20,7 @@
   , StopExtension
   , ProcessMessage
   , ProcessCommand
+  , ProcessChat
 
   -- * Strings
   , FgnStringLen(..)
@@ -45,7 +46,7 @@
   , MessageCode(..), normalMessage, errorMessage
 
   -- * process message results
-  , MessageResult(..), passMessage, dropMessage
+  , ProcessResult(..), passMessage, dropMessage
 
   -- * Marshaling helpers
   , withText0
@@ -56,72 +57,95 @@
 import           Control.Monad
 import           Data.Text (Text)
 import qualified Data.Text.Foreign as Text
+import           Data.Word
 import           Foreign.C
 import           Foreign.Marshal.Array
 import           Foreign.Ptr
 import           Foreign.Storable
 
 -- | Tag for describing the kind of message to display in the client
--- as used in `glirc_print`.
+-- as used in `glirc_print`. See 'normalMessage' and 'errorMessage'.
 --
 -- @enum message_code;@
-newtype MessageCode = MessageCode CInt deriving Eq
-#enum MessageCode, MessageCode, NORMAL_MESSAGE, ERROR_MESSAGE
+newtype MessageCode = MessageCode (#type enum message_code) deriving Eq
 
+-- | Normal client message. Unread counter increments, but no client
+-- bell or error status update.
+normalMessage :: MessageCode
+normalMessage = MessageCode (#const NORMAL_MESSAGE)
+
+-- | Important client message. Unread counter increments, bell rings,
+-- and error status updates.
+errorMessage :: MessageCode
+errorMessage = MessageCode (#const ERROR_MESSAGE)
+
 -- | Result used to determine what to do after processing a message with
 -- the 'ProcessMessage' callback.
 --
--- @enum process_result;@
-newtype MessageResult = MessageResult CInt deriving Eq
-#enum MessageResult, MessageResult, PASS_MESSAGE, DROP_MESSAGE
+-- | @enum process_result@
+newtype ProcessResult = ProcessResult (#type enum process_result) deriving Eq
 
---
+-- | Allow the message to proceed through the client logic.
+passMessage :: ProcessResult
+passMessage = ProcessResult (#const PASS_MESSAGE)
 
--- | @typedef void *start(void *glirc, const char *path);@
+-- | Drop the message from further processing.
+dropMessage :: ProcessResult
+dropMessage = ProcessResult (#const DROP_MESSAGE)
+
+-- | @typedef void *start(void *glirc, const char *path)@
 type StartExtension =
-  Ptr ()      {- ^ api token                   -} ->
-  CString     {- ^ path to extension           -} ->
-  IO (Ptr ()) {- ^ initialized extension state -}
+  Ptr ()           {- ^ api token                   -} ->
+  CString          {- ^ path to extension           -} ->
+  Ptr FgnStringLen {- ^ array of arguments          -} ->
+  CSize            {- ^ number of arguments         -} ->
+  IO (Ptr ())      {- ^ initialized extension state -}
 
--- | @typedef void stop(void *glirc, void *S);@
+-- | @typedef void stop(void *glirc, void *S)@
 type StopExtension =
   Ptr () {- ^ api token       -} ->
   Ptr () {- ^ extension state -} ->
   IO ()
 
--- | @typedef enum process_result process_message(void *glirc, void *S, const struct glirc_message *);@
+-- | @typedef enum process_result process_message(void *glirc, void *S, const struct glirc_message *)@
 type ProcessMessage =
   Ptr ()     {- ^ api token       -} ->
   Ptr ()     {- ^ extention state -} ->
   Ptr FgnMsg {- ^ message to send -} ->
-  IO MessageResult
+  IO ProcessResult
 
--- | @typedef void process_command(void *glirc, void *S, const struct glirc_command *);@
+-- | @typedef void process_command(void *glirc, void *S, const struct glirc_command *)@
 type ProcessCommand =
   Ptr ()     {- ^ api token       -} ->
   Ptr ()     {- ^ extension state -} ->
   Ptr FgnCmd {- ^ command         -} ->
   IO ()
 
--- | @typedef void process_chat(void *glirc, void *S, const struct glirc_chat *);@
+-- | @typedef void process_chat(void *glirc, void *S, const struct glirc_chat *)@
 type ProcessChat =
   Ptr ()      {- ^ api token       -} ->
   Ptr ()      {- ^ extension state -} ->
   Ptr FgnChat {- ^ chat info       -} ->
-  IO MessageResult
+  IO ProcessResult
 
--- | Type of dynamic function pointer wrappers.
+-- | Type of dynamic function pointer wrappers. These convert C
+-- function-pointers into Haskell functions.
 type Dynamic a = FunPtr a -> a
 
+-- | Dynamic import for 'StartExtension'.
 foreign import ccall "dynamic" runStartExtension :: Dynamic StartExtension
+-- | Dynamic import for 'StopExtension'.
 foreign import ccall "dynamic" runStopExtension  :: Dynamic StopExtension
+-- | Dynamic import for 'ProcessMessage'.
 foreign import ccall "dynamic" runProcessMessage :: Dynamic ProcessMessage
+-- | Dynamic import for 'ProcessCommand'.
 foreign import ccall "dynamic" runProcessCommand :: Dynamic ProcessCommand
+-- | Dynamic import for 'ProcessChat'.
 foreign import ccall "dynamic" runProcessChat    :: Dynamic ProcessChat
 
 ------------------------------------------------------------------------
 
--- | @struct glirc_extension;@
+-- | Information describing an extension's entry-points and metadata.
 data FgnExtension = FgnExtension
   { fgnStart   :: FunPtr StartExtension -- ^ Optional startup callback
   , fgnStop    :: FunPtr StopExtension  -- ^ Optional shutdown callback
@@ -132,6 +156,7 @@
   , fgnMajorVersion, fgnMinorVersion :: CInt -- ^ extension version
   }
 
+-- | @struct glirc_extension@
 instance Storable FgnExtension where
   alignment _ = #alignment struct glirc_extension
   sizeOf    _ = #size      struct glirc_extension
@@ -199,13 +224,15 @@
 
 ------------------------------------------------------------------------
 
--- | @struct glirc_message@
+-- | Chat message data containing the source network, window target,
+-- and message body.
 data FgnChat = FgnChat
   { fhNetwork    :: FgnStringLen
   , fhTarget     :: FgnStringLen
   , fhMessage    :: FgnStringLen
   }
 
+-- | @struct glirc_message@
 instance Storable FgnChat where
   alignment _ = #alignment struct glirc_chat
   sizeOf    _ = #size      struct glirc_chat
@@ -221,11 +248,13 @@
 
 ------------------------------------------------------------------------
 
--- | @struct glirc_command@
+-- | Used to pass arguments from @/extension EXT_NAME@ client command into
+-- an extension.
 data FgnCmd = FgnCmd
   { fcCommand :: FgnStringLen
   }
 
+-- | @struct glirc_command@
 instance Storable FgnCmd where
   alignment _ = #alignment struct glirc_command
   sizeOf    _ = #size      struct glirc_command
@@ -236,9 +265,11 @@
 
 ------------------------------------------------------------------------
 
--- | @struct glirc_string@
+-- | Pointer to UTF-8 encoded string and as string length. Strings are
+-- null-terminated. The null-terminator is not counted in the length.
 data FgnStringLen = FgnStringLen !CString !CSize
 
+-- | @struct glirc_string@
 instance Storable FgnStringLen where
   alignment _ = #alignment struct glirc_string
   sizeOf    _ = #size      struct glirc_string
diff --git a/src/Client/Commands.hs b/src/Client/Commands.hs
--- a/src/Client/Commands.hs
+++ b/src/Client/Commands.hs
@@ -53,7 +53,6 @@
 import qualified Data.HashMap.Strict as HashMap
 import qualified Data.Map as Map
 import           Data.Maybe (fromMaybe)
-import           Data.Monoid ((<>))
 import           Data.Text (Text)
 import qualified Data.Text as Text
 import           Data.Time
@@ -1835,8 +1834,8 @@
 computeBanUserInfo :: Identifier -> NetworkState    -> UserInfo
 computeBanUserInfo who cs =
   case view (csUser who) cs of
-    Nothing                   -> UserInfo who "*" "*"
-    Just (UserAndHost _ host) -> UserInfo "*" "*" host
+    Nothing                     -> UserInfo who "*" "*"
+    Just (UserAndHost _ host _) -> UserInfo "*" "*" host
 
 cmdRemove :: ChannelCommand (String, String)
 cmdRemove channelId cs st (who,reason) =
@@ -1968,14 +1967,14 @@
 -- Attempt to reload the configuration file
 cmdReload :: ClientCommand (Maybe String)
 cmdReload st mbPath =
-  do let path   = mbPath <|> view clientConfigPath st
+  do let path = mbPath <|> Just (view clientConfigPath st)
      res <- loadConfiguration path
      case res of
        Left e -> commandFailureMsg (describeProblem e) st
-       Right cfg ->
+       Right (path',cfg) ->
          do st1 <- clientStartExtensions
                  $ set clientConfig cfg
-                 $ set clientConfigPath mbPath st
+                 $ set clientConfigPath path' st
             commandSuccess st1
 
   where
@@ -2146,7 +2145,7 @@
     usermasks =
       [ mkId ("*!*@" <> host)
         | nick <- HashMap.keys (view (csChannels . ix channel . chanUsers) cs)
-        , UserAndHost _ host <- toListOf (csUsers . ix nick) cs
+        , UserAndHost _ host _ <- toListOf (csUsers . ix nick) cs
         ]
 
 -- | Predicate for mode commands that can be performed without ops
diff --git a/src/Client/Commands/Arguments/Renderer.hs b/src/Client/Commands/Arguments/Renderer.hs
--- a/src/Client/Commands/Arguments/Renderer.hs
+++ b/src/Client/Commands/Arguments/Renderer.hs
@@ -19,7 +19,6 @@
 import           Control.Lens
 import           Control.Monad.Trans.State
 import           Data.Functor.Compose
-import           Data.Semigroup ((<>))
 import qualified Data.Text as Text
 import           Graphics.Vty (wcswidth)
 import           Graphics.Vty.Attributes
diff --git a/src/Client/Commands/Interpolation.hs b/src/Client/Commands/Interpolation.hs
--- a/src/Client/Commands/Interpolation.hs
+++ b/src/Client/Commands/Interpolation.hs
@@ -10,6 +10,13 @@
 This module is able to parse commands with inline variables and then
 to evaluate those variables to produce a complete command that varies
 by the current context.
+
+Variables are built from 1 or more letters.
+
+Optional arguments are suffixed with a @?@
+
+Remaining text arguments are suffixed with a @*@
+
 -}
 module Client.Commands.Interpolation
   ( ExpansionChunk(..)
@@ -66,16 +73,19 @@
 
 macroSpecs :: Parser MacroSpec
 macroSpecs =
-  cons <$> P.takeWhile1 isAlpha
-       <*> optional (char '?')
-       <*  P.skipSpace
-       <*> macroSpecs
-    <|> pure (MacroSpec (pure []))
+  do var <- P.takeWhile1 isAlpha
+     mode <- optional (True <$ char '?' <|> False <$ char '*')
+     P.skipSpace
+     case mode of
+       Nothing    -> addReq var <$> macroSpecs
+       Just True  -> addOpt var <$> macroSpecs
+       Just False -> MacroSpec (pure <$> remainingArg (Text.unpack var)) <$ P.endOfInput
+  <|> noMacroArguments <$ P.endOfInput
   where
     add1 desc = liftA2 (:) (simpleToken (Text.unpack desc))
 
-    cons desc (Just _) (MacroSpec rest) = MacroSpec (fromMaybe [] <$> optionalArg (add1 desc rest))
-    cons desc Nothing  (MacroSpec rest) = MacroSpec (add1 desc rest)
+    addOpt var (MacroSpec rest) = MacroSpec (fromMaybe [] <$> optionalArg (add1 var rest))
+    addReq var (MacroSpec rest) = MacroSpec (add1 var rest)
 
 -- | Parse a 'Text' searching for the expansions as specified in
 -- 'ExpansionChunk'. @$$@ is used to escape a single @$@.
@@ -111,13 +121,14 @@
 -- the two expansion functions. If the expansion of any chunk
 -- fails the whole expansion fails.
 resolveMacroExpansions ::
-  (Text    -> Maybe Text) {- ^ variable resolution       -} ->
-  (Integer -> Maybe Text) {- ^ argument index resolution -} ->
-  [ExpansionChunk]        {- ^ chunks                    -} ->
-  Maybe Text              {- ^ concatenated, expanded chunks -}
+  Alternative f =>
+  (Text    -> f Text) {- ^ variable resolution           -} ->
+  (Integer -> f Text) {- ^ argument index resolution     -} ->
+  [ExpansionChunk]    {- ^ chunks                        -} ->
+  f Text              {- ^ concatenated, expanded chunks -}
 resolveMacroExpansions var arg xs = Text.concat <$> traverse resolve1 xs
   where
-    resolve1 (LiteralChunk lit) = Just lit
+    resolve1 (LiteralChunk lit) = pure lit
     resolve1 (VariableChunk v)  = var v
     resolve1 (IntegerChunk i)   = arg i
-    resolve1 (DefaultChunk p d) = resolve1 p <|> Just d
+    resolve1 (DefaultChunk p d) = resolve1 p <|> pure d
diff --git a/src/Client/Commands/Recognizer.hs b/src/Client/Commands/Recognizer.hs
--- a/src/Client/Commands/Recognizer.hs
+++ b/src/Client/Commands/Recognizer.hs
@@ -25,7 +25,6 @@
 import Control.Applicative hiding (empty)
 
 import           Data.HashMap.Strict (lookup,insertWith,HashMap,empty,unionWith,fromList,toList)
-import           Data.Semigroup
 import           Data.Text (Text)
 import qualified Data.Text as Text
 import           Data.Maybe
diff --git a/src/Client/Configuration.hs b/src/Client/Configuration.hs
--- a/src/Client/Configuration.hs
+++ b/src/Client/Configuration.hs
@@ -21,6 +21,7 @@
   , ConfigurationFailure(..)
   , LayoutMode(..)
   , PaddingMode(..)
+  , ExtensionConfiguration(..)
 
   -- * Lenses
   , configDefaults
@@ -41,6 +42,10 @@
   , configShowPing
   , configJumpModifier
 
+  , extensionPath
+  , extensionRtldFlags
+  , extensionArgs
+
   -- * Loading configuration
   , loadConfiguration
 
@@ -49,6 +54,11 @@
 
   -- * Specification
   , configurationSpec
+
+  -- * FilePath resolution
+  , FilePathContext
+  , newFilePathContext
+  , resolveFilePath
   ) where
 
 import           Client.Commands.Interpolation
@@ -70,7 +80,7 @@
 import qualified Data.HashSet                        as HashSet
 import qualified Data.List.NonEmpty                  as NonEmpty
 import           Data.Maybe
-import           Data.Monoid                         (Endo(..), (<>))
+import           Data.Monoid                         (Endo(..))
 import           Data.Text                           (Text)
 import qualified Data.Text                           as Text
 import qualified Data.Text.IO                        as Text
@@ -80,6 +90,7 @@
 import           System.Directory
 import           System.FilePath
 import           System.IO.Error
+import           System.Posix.DynamicLinker          (RTLDFlags(..))
 
 -- | Top-level client configuration information. When connecting to a
 -- server configuration from '_configServers' is used where possible,
@@ -92,7 +103,7 @@
   , _configExtraHighlights :: HashSet Identifier -- ^ Extra highlight nicks/terms
   , _configNickPadding     :: PaddingMode -- ^ Padding of nicks in messages
   , _configMacros          :: Recognizer Macro -- ^ command macros
-  , _configExtensions      :: [FilePath] -- ^ paths to shared library
+  , _configExtensions      :: [ExtensionConfiguration] -- ^ extensions to load
   , _configUrlOpener       :: Maybe FilePath -- ^ paths to url opening executable
   , _configIgnores         :: [Text] -- ^ initial ignore mask list
   , _configActivityBar     :: Bool -- ^ initially visibility of the activity bar
@@ -119,7 +130,6 @@
   | TwoColumn
   deriving Show
 
-makeLenses ''Configuration
 
 -- | Failure cases when loading a configuration file.
 data ConfigurationFailure
@@ -137,6 +147,18 @@
 -- | default instance
 instance Exception ConfigurationFailure
 
+-- | Configuration information for run-time loaded dynamic
+-- library extensions.
+data ExtensionConfiguration = ExtensionConfiguration
+  { _extensionPath      :: FilePath -- ^ path to shared object
+  , _extensionRtldFlags :: [RTLDFlags] -- ^ dynamic linker flags
+  , _extensionArgs      :: [Text] -- ^ arguments to the extension on startup
+  }
+  deriving Show
+
+makeLenses ''Configuration
+makeLenses ''ExtensionConfiguration
+
 -- | The default client behavior for naming windows is to use the first two
 -- rows of a QWERTY keyboard followed by the first two rows combined with
 -- SHIFT.
@@ -197,9 +219,12 @@
 
 
 -- | Load the configuration file defaulting to @~/.glirc/config@.
+--
+-- Given configuration path is optional and actual path used will
+-- be returns on success
 loadConfiguration ::
   Maybe FilePath {- ^ path to configuration file -} ->
-  IO (Either ConfigurationFailure Configuration)
+  IO (Either ConfigurationFailure (FilePath, Configuration))
 loadConfiguration mbPath = try $
   do (path,txt) <- readConfigurationFile mbPath
      def  <- loadDefaultServerSettings
@@ -215,7 +240,9 @@
                 $ Text.unpack
                 $ Text.unlines
                 $ map explainLoadError (toList es)
-       Right cfg -> resolvePaths path (cfg def)
+       Right cfg ->
+         do cfg' <- resolvePaths path (cfg def)
+            return (path, cfg')
 
 
 -- | Generate a human-readable explanation of an error arising from
@@ -249,7 +276,7 @@
                                 . over (ssTlsServerCert . mapped) res
                                 . over (ssSaslEcdsaFile . mapped) res
                                 . over (ssLogDir        . mapped) res
-     return $! over (configExtensions . mapped) res
+     return $! over (configExtensions . mapped . extensionPath) res
              . over (configServers    . mapped) resolveServerFilePaths
              $ cfg
 
@@ -272,8 +299,8 @@
                                "Modifier used to jump to a window by name. Defaults to `meta`."
      _configMacros          <- sec' mempty "macros" macroMapSpec
                                "Programmable macro commands"
-     _configExtensions      <- sec' [] "extensions" (listSpec stringSpec)
-                               "Filenames of extension libraries to load at startup"
+     _configExtensions      <- sec' [] "extensions" (listSpec extensionSpec)
+                               "extension libraries to load at startup"
      _configUrlOpener       <- optSection' "url-opener" stringSpec
                                "External command used by /url command"
      _configExtraHighlights <- sec' mempty "extra-highlights" identifierSetSpec
@@ -402,6 +429,44 @@
              "Colors used to highlight nicknames"
            : [ optSection' lbl (set l <$> attrSpec) "" | (lbl, Lens l) <- paletteMap ]
 
+extensionSpec :: ValueSpecs ExtensionConfiguration
+extensionSpec = simpleExtensionSpec <!> fullExtensionSpec
+
+-- | Default dynamic linker flags: @RTLD_LOCAL@ and @RTLD_NOW@
+defaultRtldFlags :: [RTLDFlags]
+defaultRtldFlags = [RTLD_LOCAL, RTLD_NOW]
+
+-- | Given only a filepath build an extension configuration that
+-- loads the extension using the 'defaultRtldFlags' and no arguments.
+simpleExtensionSpec :: ValueSpecs ExtensionConfiguration
+simpleExtensionSpec =
+  do _extensionPath <- stringSpec
+     pure ExtensionConfiguration
+       { _extensionRtldFlags = defaultRtldFlags
+       , _extensionArgs      = []
+       , .. }
+
+-- | Full extension configuration allows the RTLD flags to be manually
+-- specified. This can be useful if the extension defines symbols that
+-- need to be visible to libraries that the extension is linked against.
+fullExtensionSpec :: ValueSpecs ExtensionConfiguration
+fullExtensionSpec =
+  sectionsSpec "extension" $
+  do _extensionPath      <- reqSection' "path"       stringSpec
+                            "Path to shared object"
+     _extensionRtldFlags <- fromMaybe defaultRtldFlags <$>
+                            optSection' "rtld-flags" (listSpec rtldFlagSpec)
+                            "Runtime dynamic linker flags"
+     _extensionArgs      <- fromMaybe [] <$> optSection "args"
+                            "Extension-specific configuration arguments"
+     pure ExtensionConfiguration {..}
+
+rtldFlagSpec :: ValueSpecs RTLDFlags
+rtldFlagSpec = namedSpec "rtld-flag"
+             $ RTLD_LOCAL  <$ atomSpec "local"
+           <!> RTLD_GLOBAL <$ atomSpec "global"
+           <!> RTLD_NOW    <$ atomSpec "now"
+           <!> RTLD_LAZY   <$ atomSpec "lazy"
 
 buildServerMap ::
   ServerSettings {- ^ defaults -} ->
diff --git a/src/Client/Configuration/Macros.hs b/src/Client/Configuration/Macros.hs
--- a/src/Client/Configuration/Macros.hs
+++ b/src/Client/Configuration/Macros.hs
@@ -28,11 +28,11 @@
   do name     <- reqSection "name" ""
      spec     <- fromMaybe noMacroArguments
              <$> optSection' "arguments" macroArgumentsSpec ""
-     commands <- reqSection' "commands" (listSpec macroCommandSpec) ""
+     commands <- reqSection' "commands" (oneOrList macroCommandSpec) ""
      return (name, Macro spec commands)
 
 macroArgumentsSpec :: ValueSpecs MacroSpec
-macroArgumentsSpec = customSpec "macro arguments" valuesSpec parseMacroSpecs
+macroArgumentsSpec = customSpec "macro-arguments" valuesSpec parseMacroSpecs
 
 macroCommandSpec :: ValueSpecs [ExpansionChunk]
-macroCommandSpec = customSpec "macro command" valuesSpec parseExpansion
+macroCommandSpec = customSpec "macro-command" valuesSpec parseExpansion
diff --git a/src/Client/EventLoop/Actions.hs b/src/Client/EventLoop/Actions.hs
--- a/src/Client/EventLoop/Actions.hs
+++ b/src/Client/EventLoop/Actions.hs
@@ -34,7 +34,6 @@
 import qualified Data.Map as Map
 import           Data.HashMap.Lazy (HashMap)
 import qualified Data.HashMap.Lazy as HashMap
-import           Data.Semigroup ((<>))
 import           Data.Text (Text)
 import qualified Data.Text as Text
 import           Text.Read
diff --git a/src/Client/Hook.hs b/src/Client/Hook.hs
--- a/src/Client/Hook.hs
+++ b/src/Client/Hook.hs
@@ -31,10 +31,11 @@
 -- handle a message ('PassMessage'), filter out a message ('OmitMessage'),
 -- or change a message into an arbitrary other message ('RemapMessage').
 data MessageResult
-  = PassMessage
-  | OmitMessage
-  | RemapMessage IrcMsg
+  = PassMessage -- ^ continue processing
+  | OmitMessage -- ^ stop processing and drop message
+  | RemapMessage IrcMsg -- ^ stop processing and return new message
 
+-- 'PassMessage' is an identity element
 instance Semigroup MessageResult where
   PassMessage <> r = r
   l           <> _ = l
diff --git a/src/Client/Hook/Znc/Buffextras.hs b/src/Client/Hook/Znc/Buffextras.hs
--- a/src/Client/Hook/Znc/Buffextras.hs
+++ b/src/Client/Hook/Znc/Buffextras.hs
@@ -17,7 +17,6 @@
   ( buffextrasHook
   ) where
 
-import           Control.Monad
 import           Data.Attoparsec.Text as P
 import           Data.Text as Text hiding (head)
 
@@ -51,12 +50,12 @@
 prefixedParser chan = do
     pfx <- prefixParser
     choice
-      [ Join pfx chan <$ skipToken "joined"
-      , Quit pfx . filterEmpty <$ skipToken "quit with message:" <*> parseReason
-      , Part pfx chan . filterEmpty <$ skipToken "parted with message:" <*> parseReason
+      [ Join pfx chan "" <$ skipToken "joined"
+      , Quit pfx . filterEmpty <$ skipToken "quit:" <*> P.takeText
+      , Part pfx chan . filterEmpty <$ skipToken "parted:" <*> P.takeText
       , Nick pfx . mkId <$ skipToken "is now known as" <*> simpleTokenParser
       , Mode pfx chan <$ skipToken "set mode:" <*> allTokens
-      , Kick pfx chan <$ skipToken "kicked" <*> parseId <* skipToken "Reason:" <*> parseReason
+      , Kick pfx chan <$ skipToken "kicked" <*> parseId <* skipToken "with reason:" <*> P.takeText
       , Topic pfx chan <$ skipToken "changed the topic to:" <*> P.takeText
       ]
 
@@ -73,9 +72,3 @@
 filterEmpty txt
   | Text.null txt = Nothing
   | otherwise     = Just txt
-
-parseReason :: Parser Text
-parseReason =
-  do txt <- char '[' *> P.takeText
-     guard (not (Text.null txt) && Text.last txt == ']')
-     return (Text.init txt)
diff --git a/src/Client/Image/Message.hs b/src/Client/Image/Message.hs
--- a/src/Client/Image/Message.hs
+++ b/src/Client/Image/Message.hs
@@ -149,8 +149,8 @@
   case body of
     IrcBody irc | NormalRender   <- rm -> ircLineImage     params irc
                 | DetailedRender <- rm -> fullIrcLineImage params irc
-    ErrorBody  txt                     -> text' defAttr (cleanText txt)
-    NormalBody txt                     -> text' defAttr (cleanText txt)
+    ErrorBody  txt                     -> parseIrcText txt
+    NormalBody txt                     -> parseIrcText txt
 
 -- | Render a 'ZonedTime' as time using quiet attributes
 --
@@ -257,7 +257,9 @@
     BatchStart{}   -> mempty
     BatchEnd{}     -> mempty
 
+    Account user _ -> who user <> " account:"
 
+
 -- | Render a chat message given a rendering mode, the sigils of the user
 -- who sent the message, and a list of nicknames to highlight.
 ircLineImage ::
@@ -297,6 +299,8 @@
     Cap _ args        -> separatedParams args
     Mode _ _ params   -> ircWords params
 
+    Account _ acct -> if Text.null acct then "*" else text' defAttr (cleanText acct)
+
 -- | Render a chat message given a rendering mode, the sigils of the user
 -- who sent the message, and a list of nicknames to highlight.
 fullIrcLineImage ::
@@ -320,9 +324,12 @@
       " is now known as " <>
       coloredIdentifier pal NormalIdentifier myNicks new
 
-    Join nick _chan ->
+    Join nick _chan acct ->
       string quietAttr "join " <>
-      coloredUserInfo pal rm myNicks nick
+      coloredUserInfo pal rm myNicks nick <>
+      if Text.null acct
+        then mempty
+        else " " <> text' quietAttr (cleanText acct)
 
     Part nick _chan mbreason ->
       string quietAttr "part " <>
@@ -417,16 +424,23 @@
     BatchStart{}   -> "BATCH +"
     BatchEnd{}     -> "BATCH -"
 
+    Account src acct ->
+      string quietAttr "acct " <>
+      who src <> ": " <>
+      if Text.null acct then "*" else text' defAttr (cleanText acct)
 
+
 renderCapCmd :: CapCmd -> Text
 renderCapCmd cmd =
   case cmd of
-    CapLs   -> "caps available"
-    CapList -> "caps active"
-    CapAck  -> "caps acknowledged"
-    CapNak  -> "caps rejected"
-    CapEnd  -> "caps finished" -- server shouldn't send this
-    CapReq  -> "caps requested" -- server shouldn't send this
+    CapLs   -> "caps-available"
+    CapList -> "caps-active"
+    CapAck  -> "caps-acknowledged"
+    CapNak  -> "caps-rejected"
+    CapEnd  -> "caps-finished" -- server shouldn't send this
+    CapReq  -> "caps-requested" -- server shouldn't send this
+    CapNew  -> "caps-offered"
+    CapDel  -> "caps-withdrawn"
 
 separatorImage :: Image'
 separatorImage = char (withForeColor defAttr blue) '·'
diff --git a/src/Client/Image/MircFormatting.hs b/src/Client/Image/MircFormatting.hs
--- a/src/Client/Image/MircFormatting.hs
+++ b/src/Client/Image/MircFormatting.hs
@@ -25,7 +25,6 @@
 import           Data.Bits
 import           Data.Char
 import           Data.Maybe
-import           Data.Semigroup ((<>))
 import           Data.Text (Text)
 import           Graphics.Vty.Attributes
 
diff --git a/src/Client/Message.hs b/src/Client/Message.hs
--- a/src/Client/Message.hs
+++ b/src/Client/Message.hs
@@ -83,7 +83,7 @@
 ircSummary :: IrcMsg -> IrcSummary
 ircSummary msg =
   case msg of
-    Join who _      -> JoinSummary (userNick who)
+    Join who _ _    -> JoinSummary (userNick who)
     Part who _ _    -> PartSummary (userNick who)
     Quit who _      -> QuitSummary (userNick who)
     Nick who who'   -> NickSummary (userNick who) who'
diff --git a/src/Client/State.hs b/src/Client/State.hs
--- a/src/Client/State.hs
+++ b/src/Client/State.hs
@@ -169,7 +169,7 @@
   , _clientNetworkMap        :: !(HashMap Text NetworkId) -- ^ network name to connection ID
 
   , _clientConfig            :: !Configuration            -- ^ client configuration
-  , _clientConfigPath        :: !(Maybe FilePath)         -- ^ client configuration file path
+  , _clientConfigPath        :: !FilePath                 -- ^ client configuration file path
 
   , _clientTextBox           :: !Edit.EditBox             -- ^ primary text box
   , _clientTextBoxOffset     :: !Int                      -- ^ size to crop from left of text box
@@ -240,7 +240,7 @@
 clientLine = views (clientTextBox . Edit.line) (\(Edit.Line n t) -> (n, t))
 
 -- | Construct an initial 'ClientState' using default values.
-withClientState :: Maybe FilePath -> Configuration -> (ClientState -> IO a) -> IO a
+withClientState :: FilePath -> Configuration -> (ClientState -> IO a) -> IO a
 withClientState cfgPath cfg k =
 
   withExtensionState $ \exts ->
diff --git a/src/Client/State/Focus.hs b/src/Client/State/Focus.hs
--- a/src/Client/State/Focus.hs
+++ b/src/Client/State/Focus.hs
@@ -28,7 +28,6 @@
   ) where
 
 import           Control.Lens
-import           Data.Monoid ((<>))
 import           Data.Text (Text)
 import           Irc.Identifier
 
diff --git a/src/Client/State/Network.hs b/src/Client/State/Network.hs
--- a/src/Client/State/Network.hs
+++ b/src/Client/State/Network.hs
@@ -48,6 +48,9 @@
 
   -- * User information
   , UserAndHost(..)
+  , uhUser
+  , uhHost
+  , uhAccount
 
   -- * Cross-message state
   , Transaction(..)
@@ -140,9 +143,11 @@
   deriving Show
 
 -- | Pair of username and hostname. Empty strings represent missing information.
-data UserAndHost =
-  UserAndHost {-# UNPACK #-} !Text {-# UNPACK #-} !Text
-  -- ^ username hostname
+data UserAndHost = UserAndHost
+  { _uhUser    :: {-# UNPACK #-}!Text -- ^ username
+  , _uhHost    :: {-# UNPACK #-}!Text -- ^ hostname
+  , _uhAccount :: {-# UNPACK #-}!Text -- ^ services account
+  }
   deriving Show
 
 -- | Status of the ping timer
@@ -164,9 +169,11 @@
   | NamesTransaction [Text]
   | BanTransaction [(Text,MaskListEntry)]
   | WhoTransaction [UserInfo]
+  | CapTransaction
   deriving Show
 
 makeLenses ''NetworkState
+makeLenses ''UserAndHost
 makePrisms ''Transaction
 makePrisms ''PingStatus
 makePrisms ''TimedAction
@@ -189,12 +196,26 @@
   where
     transmit = send (view csSocket cs) . renderRawIrcMsg
 
+    actionPrefix = "\^AACTION "
+    actionSuffix = "\^A"
+
+    -- Special case for splitting a single CTCP ACTION into
+    -- multiple actions
+    multiline cmd tgt txt
+      | Just txt1 <- Text.stripPrefix actionPrefix txt
+      , Just txt2 <- Text.stripSuffix actionSuffix txt1 =
+      let txtChunks     = utf8ChunksOf maxContentLen txt2
+          maxContentLen = computeMaxMessageLength (view csUserInfo cs) tgt
+                        - Text.length actionPrefix - Text.length actionSuffix
+      in for_ txtChunks $ \txtChunk ->
+           transmit $ rawIrcMsg cmd [tgt, actionPrefix <> txtChunk <> actionSuffix]
+
+    -- Normal case
     multiline cmd tgt txt =
-      for_ txtChunks $ \txtChunk ->
-        transmit $ rawIrcMsg cmd [tgt, txtChunk]
-      where
-        txtChunks = utf8ChunksOf maxContentLen txt
-        maxContentLen = computeMaxMessageLength (view csUserInfo cs) tgt
+      let txtChunks     = utf8ChunksOf maxContentLen txt
+          maxContentLen = computeMaxMessageLength (view csUserInfo cs) tgt
+      in for_ txtChunks $ \txtChunk ->
+           transmit $ rawIrcMsg cmd [tgt, txtChunk]
 
 -- This is an approximation for splitting the text. It doesn't
 -- understand combining characters. A correct implementation
@@ -238,7 +259,7 @@
   , _csSocket       = sock
   , _csChannelTypes = defaultChannelTypes
   , _csModeTypes    = defaultModeTypes
-  , _csTransaction  = NoTransaction
+  , _csTransaction  = CapTransaction
   , _csModes        = ""
   , _csStatusMsg    = ""
   , _csSettings     = settings
@@ -276,12 +297,16 @@
   case msg of
     Ping args -> ([ircPong args], cs)
     Pong _    -> noReply $ doPong msgWhen cs
-    Join user chan ->
+    Join user chan acct ->
            noReply
-         $ recordUser user
+         $ recordUser user acct
          $ overChannel chan (joinChannel (userNick user))
          $ createOnJoin user chan cs
 
+    Account user acct ->
+           noReply
+         $ recordUser user acct cs
+
     Quit user _reason ->
            noReply
          $ forgetUser (userNick user)
@@ -298,10 +323,18 @@
          $ overChannels (nickChange (userNick oldNick) newNick) cs
 
     Reply RPL_WELCOME (me:_) -> doWelcome msgWhen (mkId me) cs
-    Reply RPL_SASLSUCCESS _ -> ([ircCapEnd], cs)
-    Reply RPL_SASLFAIL _ -> ([ircCapEnd], cs)
+    Reply RPL_SASLSUCCESS _ -> endCapTransaction cs
+    Reply RPL_SASLFAIL _ -> endCapTransaction cs
     Reply ERR_NICKNAMEINUSE (_:badnick:_)
       | PingConnecting{} <- view csPingStatus cs -> doBadNick badnick cs
+    Reply RPL_HOSTHIDDEN (_:host:_) ->
+        noReply (set (csUserInfo . uiHost) host cs)
+
+    -- /who <#channel> %tuhna,616
+    Reply RPL_WHOSPCRPL [_me,"616",user,host,nick,acct] ->
+       let acct' = if acct == "0" then "" else acct
+       in noReply (recordUser (UserInfo (mkId nick) user host) acct' cs)
+
     Reply code args        -> noReply (doRpl code msgWhen args cs)
     Cap cmd params         -> doCap cmd params cs
     Authenticate param     -> doAuthenticate param cs
@@ -336,6 +369,7 @@
   . set csNick me
   . set csNextPingTime (Just $! addUTCTime 30 (zonedTimeToUTC msgWhen))
   . set csPingStatus PingNone
+  . set csTransaction NoTransaction -- wipe out CapTransaction if it was active
 
 -- | Handle 'ERR_NICKNAMEINUSE' errors when connecting.
 doBadNick ::
@@ -540,6 +574,7 @@
     RPL_UMODEIS         -> True
     RPL_WHOREPLY        -> True
     RPL_ENDOFWHO        -> True
+    RPL_WHOSPCRPL       -> True
     RPL_TOPICWHOTIME    -> True
     RPL_CREATIONTIME    -> True
     RPL_CHANNEL_URL     -> True
@@ -631,11 +666,24 @@
       | otherwise         = mode:modes
     applyOne modes (False, mode, _) = delete mode modes
 
-supportedCaps :: NetworkState -> [Text]
-supportedCaps cs =
-  sasl ++ ["multi-prefix", "batch", "znc.in/playback",
-           "server-time", "znc.in/self-message"]
+selectCaps ::
+  NetworkState {- ^ network state  -} ->
+  [Text]       {- ^ server caps    -} ->
+  [Text]       {- ^ caps to enable -}
+selectCaps cs offered = supported `intersect` offered
   where
+    supported =
+      sasl ++ serverTime ++
+      ["multi-prefix", "batch", "znc.in/playback", "znc.in/self-message"
+      , "cap-notify", "extended-join", "account-notify" ]
+
+    -- logic for using IRCv3.2 server-time if available and falling back
+    -- to ZNC's specific extension otherwise.
+    serverTime
+      | "server-time"            `elem` offered = ["server-time"]
+      | "znc.in/server-time-iso" `elem` offered = ["znc.in/server-time-iso"]
+      | otherwise                               = []
+
     ss = view csSettings cs
     sasl = ["sasl" | isJust (view ssSaslUsername ss)
                    , isJust (view ssSaslPassword ss) ||
@@ -669,25 +717,41 @@
 doCap cmd args cs =
   case (cmd,args) of
     (CapLs,[capsTxt])
-      | null reqCaps -> ([ircCapEnd], cs)
+      | null reqCaps -> endCapTransaction cs
       | otherwise -> ([ircCapReq reqCaps], cs)
       where
         caps = Text.words capsTxt
-        reqCaps = intersect (supportedCaps cs) caps
+        reqCaps = selectCaps cs caps
 
+    (CapNew,[capsTxt])
+      | null reqCaps -> ([], cs)
+      | otherwise -> ([ircCapReq reqCaps], cs)
+      where
+        caps = Text.words capsTxt
+        reqCaps = selectCaps cs caps
+
+    (CapDel,_) -> ([],cs)
+
     (CapAck,[capsTxt])
       | "sasl" `elem` caps ->
           if isJust (view ssSaslEcdsaFile ss)
-            then ([ircAuthenticate Ecdsa.authenticationMode], set csAuthenticationState AS_EcdsaStarted cs)
+            then ( [ircAuthenticate Ecdsa.authenticationMode]
+                 , set csAuthenticationState AS_EcdsaStarted cs)
           else if isJust (view ssSaslUsername ss)
-            then ([ircAuthenticate plainAuthenticationMode], set csAuthenticationState AS_PlainStarted cs)
-          else ([ircCapEnd], cs)
+            then ( [ircAuthenticate plainAuthenticationMode]
+                 , set csAuthenticationState AS_PlainStarted cs)
+          else endCapTransaction cs
       where
         ss   = view csSettings cs
         caps = Text.words capsTxt
 
-    _ -> ([ircCapEnd], cs)
+    _ -> endCapTransaction cs
 
+endCapTransaction :: NetworkState -> ([RawIrcMsg], NetworkState)
+endCapTransaction cs =
+  case view csTransaction cs of
+    CapTransaction -> ([ircCapEnd], set csTransaction NoTransaction cs)
+    _              -> ([], cs)
 
 initialMessages :: NetworkState -> [RawIrcMsg]
 initialMessages cs
@@ -800,11 +864,11 @@
 csUser :: Functor f => Identifier -> LensLike' f NetworkState (Maybe UserAndHost)
 csUser i = csUsers . at i
 
-recordUser :: UserInfo -> NetworkState -> NetworkState
-recordUser (UserInfo nick user host)
+recordUser :: UserInfo -> Text -> NetworkState -> NetworkState
+recordUser (UserInfo nick user host) acct
   | Text.null user || Text.null host = id
   | otherwise = set (csUsers . at nick)
-                    (Just (UserAndHost user host))
+                    (Just $! UserAndHost user host acct)
 
 forgetUser :: Identifier -> NetworkState -> NetworkState
 forgetUser = over csUsers . sans
@@ -838,7 +902,11 @@
       | not (Text.null user)
       , not (Text.null host)
       , HashSet.member nick channelUsers =
-              HashMap.insert nick (UserAndHost user host) users
+            HashMap.alter
+                (\mb -> case mb of
+                          Nothing                     -> Just $! UserAndHost user host ""
+                          Just (UserAndHost _ _ acct) -> Just $! UserAndHost user host acct
+                ) nick users
       | otherwise = users
 
 -- | Compute the earliest timed action for a connection, if any
diff --git a/src/Client/View/Palette.hs b/src/Client/View/Palette.hs
--- a/src/Client/View/Palette.hs
+++ b/src/Client/View/Palette.hs
@@ -42,17 +42,23 @@
 paletteViewLines :: Palette -> [Image']
 paletteViewLines pal = reverse $
 
-  [ "Current client palette"
+  [ "Current client palette:"
   , ""
   , columns (paletteEntries pal)
   , ""
 
-  , "Current client palette nick highlight colors"
+  , "Current client palette nick highlight colors:"
   , ""
   , columns (nickHighlights pal)
   , ""
 
-  , "Chat formatting colors: ^C[foreground[,background]]"
+  , "Chat formatting modes:"
+  , ""
+  , "   C-b  C-_       C-]    C-v     C-o"
+  , parseIrcText "   \^Bbold\^B \^_underline\^_ \^]italic\^] \^Vreverse\^V reset"
+  , ""
+
+  , "Chat formatting colors: C-c[foreground[,background]]"
   , ""
   , columns ("   " : map decimalImage [0..15])
   , columns mircColors
diff --git a/src/Client/View/RtsStats.hs b/src/Client/View/RtsStats.hs
--- a/src/Client/View/RtsStats.hs
+++ b/src/Client/View/RtsStats.hs
@@ -1,4 +1,4 @@
-{-# Language CPP, OverloadedStrings #-}
+{-# Language OverloadedStrings #-}
 {-|
 Module      : Client.View.RtsStats
 Description : View current GHC RTS statistics
@@ -6,8 +6,7 @@
 License     : ISC
 Maintainer  : emertens@gmail.com
 
-Lines for the @/rtsstats@ command. This module depends
-on GHC 8.2.1 API.
+Lines for the @/rtsstats@ command.
 
 -}
 
@@ -26,7 +25,7 @@
 rtsStatsLines Nothing pal = [text' (view palError pal) "Statistics not available"]
 rtsStatsLines (Just stats) pal
   | null entries = [text' (view palError pal) "Statistics empty"]
-  | otherwise    = zipWith (\v l -> padV wv v <> " " <> l) valueImages labelImages 
+  | otherwise    = zipWith (\v l -> padV wv v <> " " <> l) valueImages labelImages
   where
     entries     = statsToEntries stats
     labelImages = map (text' (view palLabel pal) . fst) entries
diff --git a/src/Client/View/UserList.hs b/src/Client/View/UserList.hs
--- a/src/Client/View/UserList.hs
+++ b/src/Client/View/UserList.hs
@@ -114,21 +114,22 @@
 
     pal = clientPalette st
 
-    renderEntry (info, sigils) =
+    renderEntry ((info, acct), sigils) =
       string (view palSigil pal) sigils <>
-      coloredUserInfo pal DetailedRender myNicks info
+      coloredUserInfo pal DetailedRender myNicks info <>
+      " " <> text' (view palMeta pal) (cleanText acct)
 
-    matcher' (info,sigils) =
-      matcher (LText.fromChunks [Text.pack sigils, renderUserInfo info])
+    matcher' ((info, acct),sigils) =
+      matcher (LText.fromChunks [Text.pack sigils, renderUserInfo info, " ", acct])
 
     userInfos = view csUsers cs
 
     toInfo nick =
       case view (at nick) userInfos of
-        Just (UserAndHost n h) -> UserInfo nick n h
-        Nothing                -> UserInfo nick "" ""
+        Just (UserAndHost n h a) -> (UserInfo nick n h, a)
+        Nothing                  -> (UserInfo nick "" "", "")
 
-    usersList = sortBy (flip (comparing (userNick . fst)))
+    usersList = sortBy (flip (comparing (userNick . fst . fst)))
               $ filter matcher'
               $ map (over _1 toInfo)
               $ HashMap.toList usersHashMap
diff --git a/src/RtsStats.hs b/src/RtsStats.hs
--- a/src/RtsStats.hs
+++ b/src/RtsStats.hs
@@ -1,8 +1,8 @@
-{-# Language OverloadedStrings, CPP #-}
+{-# Language OverloadedStrings #-}
 
 {-|
 Module      : RtsStats
-Description : Compatibility layer for GHC RTS statistics across versions
+Description : Human readable interface to GHC RTS statistics
 Copyright   : (c) Eric Mertens, 2017
 License     : ISC
 Maintainer  : emertens@gmail.com
@@ -15,12 +15,12 @@
   , statsToEntries
   ) where
 
-import           Data.Int
-import           Data.List (intercalate)
+import           Data.Int        (Int64)
+import           Data.List       (intercalate)
 import           Data.List.Split (chunksOf)
-import           Data.Text (Text)
+import           Data.Text       (Text)
 import qualified Data.Text as Text
-import           Data.Word
+import           Data.Word       (Word32, Word64)
 import           GHC.Stats
 
 class    Render a      where render :: a -> Text
@@ -37,8 +37,6 @@
 addCommas :: String -> String
 addCommas = reverse . intercalate "," . chunksOf 3 . reverse
 
-#if MIN_VERSION_base(4,10,0)
-
 newtype Stats = Stats RTSStats
 
 getStats :: IO (Maybe Stats)
@@ -48,7 +46,8 @@
                 else pure Nothing
 
 statsToEntries :: Stats -> [(Text, Text)]
-statsToEntries (Stats rts) = seq rgc
+statsToEntries (Stats rts) =
+  let rgc = gc rts in seq rgc
   [ ("GCs"                                 , render $ gcs                             rts)
   , ("Major GCs"                           , render $ major_gcs                       rts)
   , ("Allocated bytes"                     , render $ allocated_bytes                 rts)
@@ -84,42 +83,3 @@
   , ("Elapsed ns"                          , render $ gcdetails_elapsed_ns            rgc)
   , ("==[Last GC]=="                       , ""                                          )
   ]
-  where
-    rgc = gc rts
-
-#else
-
-statsToEntries :: Stats -> [(Text, Text)]
-statsToEntries (Stats rts) = seq rts
-  [ ("Allocated bytes"            , render $ bytesAllocated         rts)
-  , ("GCs"                        , render $ numGcs                 rts)
-  , ("Major GCs"                  , render $ numByteUsageSamples    rts)
-  , ("Cumulative allocated bytes" , render $ maxBytesUsed           rts)
-  , ("Cumulative live bytes"      , render $ cumulativeBytesUsed    rts)
-  , ("Cumulative copied  bytes"   , render $ bytesCopied            rts)
-  , ("Max slop bytes"             , render $ maxBytesSlop           rts)
-  , ("Maximum allocated megabytes", render $ peakMegabytesAllocated rts)
-  , ("Mutator CPU seconds"        , render $ mutatorCpuSeconds      rts)
-  , ("Mutator elapsed seconds"    , render $ mutatorWallSeconds     rts)
-  , ("GC CPU seconds"             , render $ gcCpuSeconds           rts)
-  , ("GC elapsed seconds"         , render $ gcWallSeconds          rts)
-  , ("CPU seconds"                , render $ cpuSeconds             rts)
-  , ("Elapsed seconds"            , render $ wallSeconds            rts)
-  , ("Total bytes copied"         , render $ parTotBytesCopied      rts)
-  , ("Max parallel bytes copied"  , render $ parMaxBytesCopied      rts)
-  , ("==[Totals]=="               , ""                                 )
-  , (""                           , ""                                 )
-  , ("(last) Live bytes"          , render $ currentBytesUsed       rts)
-  , ("(last) Slop bytes"          , render $ currentBytesSlop       rts)
-  , ("==[Last GC]=="              , ""                                 )
-  ]
-
-newtype Stats = Stats GCStats
-
-getStats :: IO (Maybe Stats)
-getStats =
-  do enabled <- getGCStatsEnabled
-     if enabled then Just . Stats <$> getGCStats
-                else pure Nothing
-
-#endif
diff --git a/src/StrictUnit.hs b/src/StrictUnit.hs
--- a/src/StrictUnit.hs
+++ b/src/StrictUnit.hs
@@ -15,7 +15,7 @@
   ( StrictUnit(..)
   ) where
 
-import           Data.Semigroup
+import           Data.Semigroup (stimes, stimesIdempotent)
 
 -- | Unit data type with a strict 'Semigroup' and 'Monoid' instances.
 data StrictUnit = StrictUnit