diff --git a/changelog.md b/changelog.md
new file mode 100644
--- /dev/null
+++ b/changelog.md
@@ -0,0 +1,3 @@
+1.0.0.0
+
+  * Initial release
diff --git a/library/Skylighting/Extensions.hs b/library/Skylighting/Extensions.hs
new file mode 100644
--- /dev/null
+++ b/library/Skylighting/Extensions.hs
@@ -0,0 +1,43 @@
+{-# OPTIONS_GHC -Wall #-}
+
+{-# LANGUAGE OverloadedStrings #-}
+
+{- |
+
+Provides a miscellaneous assortment of customized Skylighting syntax
+highlighters.
+
+-}
+
+module Skylighting.Extensions (extendedSyntaxMap, applyAll) where
+
+import qualified Skylighting.Extensions.GHCi
+import qualified Skylighting.Extensions.Haskell
+
+-- skylighting
+import Skylighting (SyntaxMap)
+import qualified Skylighting
+
+-- skylighting-modding
+import Skylighting.Modding
+
+{- |
+
+The default Skylighting syntax map, plus all of the extensions provided by
+the @skylighting-extensions@ library.
+
+-}
+
+extendedSyntaxMap :: SyntaxMap
+extendedSyntaxMap = applyAll Skylighting.defaultSyntaxMap
+
+{- |
+
+Apply all of the syntax extensions in the @skylighting-extensions@ library.
+
+-}
+
+applyAll :: SyntaxMap -> SyntaxMap
+applyAll =
+    addSyntax Skylighting.Extensions.GHCi.syntax .
+    modifySyntax "Haskell" Skylighting.Extensions.Haskell.expandKeywordSet
diff --git a/library/Skylighting/Extensions/GHCi.hs b/library/Skylighting/Extensions/GHCi.hs
new file mode 100644
--- /dev/null
+++ b/library/Skylighting/Extensions/GHCi.hs
@@ -0,0 +1,79 @@
+{-# OPTIONS_GHC -Wall #-}
+
+{-# LANGUAGE OverloadedStrings #-}
+
+{- |
+
+Introduces a new Skylighting syntax highlighter for GHCi (a REPL for Haskell).
+
+-}
+
+module Skylighting.Extensions.GHCi (syntax) where
+
+-- skylighting-core
+import Skylighting.Core
+
+-- skylighting-modding
+import Skylighting.Modding
+
+-- text
+import qualified Data.Text.Encoding as Text
+
+{- |
+
+A Skylighting 'Syntax' for highlighting GHCi sessions. The only thing this does
+is highlight prompts. We assume that the prompt is @"λ>"@ and the continuation
+prompt is @" >"@.
+
+-}
+
+syntax :: Syntax
+syntax =
+    Syntax
+        { sName = "ghci"
+        , sFilename = ""
+        , sShortname = "ghci"
+        , sContexts = contextMap ghciContext
+        , sAuthor = "Typeclass Consulting, LLC"
+        , sVersion = "1"
+        , sLicense = "MIT"
+        , sExtensions = []
+        , sStartingContext = "ghci"
+        }
+
+ghciContext :: Context
+ghciContext =
+    Context
+        { cName = "ghci"
+        , cSyntax = "ghci"
+        , cRules = [promptRule]
+        , cAttribute = NormalTok
+        , cLineEmptyContext = []
+        , cLineEndContext = []
+        , cLineBeginContext = []
+        , cFallthrough = False
+        , cFallthroughContext = []
+        , cDynamic = False
+        }
+
+promptRule :: Rule
+promptRule =
+    Rule
+        { rMatcher = RegExpr promptRE
+        , rAttribute = AnnotationTok
+        , rIncludeAttribute = True
+        , rDynamic = False
+        , rCaseSensitive = True
+        , rChildren = []
+        , rLookahead = False
+        , rFirstNonspace = False
+        , rColumn = Just 0
+        , rContextSwitch = []
+        }
+
+promptRE :: RE
+promptRE =
+    RE
+        { reString = Text.encodeUtf8 "[λ ]>"
+        , reCaseSensitive = True
+        }
diff --git a/library/Skylighting/Extensions/Haskell.hs b/library/Skylighting/Extensions/Haskell.hs
new file mode 100644
--- /dev/null
+++ b/library/Skylighting/Extensions/Haskell.hs
@@ -0,0 +1,92 @@
+{-# OPTIONS_GHC -Wall #-}
+
+{-# LANGUAGE OverloadedStrings #-}
+
+{- |
+
+Modifications for the default Skylighting syntax highlighter for Haskell.
+
+-}
+
+module Skylighting.Extensions.Haskell (expandKeywordSet, keywords) where
+
+-- containers
+import qualified Data.Set as Set
+
+-- skylighting-core
+import Skylighting.Core
+
+-- skylighting-modding
+import Skylighting.Modding
+
+-- text
+import Data.Text (Text)
+
+{- |
+
+Modifies Skylighting's default Haskell syntax so that the list of keywords
+includes ones that are introduced by GHC extensions (enumerated by 'keywords').
+
+-}
+
+expandKeywordSet :: Syntax -> Syntax
+expandKeywordSet =
+    modifySyntaxContexts $
+        modifyContext "code" $
+            replaceKeywordRule keywordRule
+
+keywordRule :: Rule
+keywordRule =
+    Rule
+        { rMatcher = keywordMatcher
+        , rAttribute = KeywordTok
+        , rIncludeAttribute = False
+        , rDynamic = False
+        , rCaseSensitive = True
+        , rChildren = []
+        , rLookahead = False
+        , rFirstNonspace = False
+        , rColumn = Nothing
+        , rContextSwitch = []
+        }
+
+keywordMatcher :: Matcher
+keywordMatcher = Keyword keywordAttr (makeWordSet True keywords)
+
+keywordAttr :: KeywordAttr
+keywordAttr =
+    KeywordAttr
+        { keywordCaseSensitive = True
+        , keywordDelims = Set.fromList "\t\n !%&()*+,-./:;<=>?[\\]^{|}~"
+        }
+
+{- |
+
+A list of keywords for Haskell, including ones introduced by GHC extensions.
+
+-}
+
+keywords :: [Text]
+keywords =
+    [ "case"
+    , "class"
+    , "data"
+    , "deriving"
+    , "do"
+    , "else"
+    , "forall" -- ExplicitForAll
+    , "if"
+    , "in"
+    , "infixl"
+    , "infixr"
+    , "instance"
+    , "let"
+    , "module"
+    , "newtype"
+    , "of"
+    , "primitive"
+    , "then"
+    , "type"
+    , "via" -- DerivingVia
+    , "where"
+    ]
diff --git a/license.txt b/license.txt
new file mode 100644
--- /dev/null
+++ b/license.txt
@@ -0,0 +1,18 @@
+Copyright 2019 Typeclass Consulting, LLC
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of
+this software and associated documentation files (the "Software"), to deal in
+the Software without restriction, including without limitation the rights to
+use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+the Software, and to permit persons to whom the Software is furnished to do so,
+subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
diff --git a/skylighting-extensions.cabal b/skylighting-extensions.cabal
new file mode 100644
--- /dev/null
+++ b/skylighting-extensions.cabal
@@ -0,0 +1,42 @@
+cabal-version: 2.0
+
+name: skylighting-extensions
+version: 1.0.0.0
+
+synopsis: Customized Skylighting syntax highlighters
+category: Text
+
+description:
+    A miscellaneous assortment of customized Skylighting syntax highlighters.
+
+homepage:    https://github.com/typeclasses/pandoc-highlighting-ext
+bug-reports: https://github.com/typeclasses/pandoc-highlighting-ext/issues
+
+author:     Chris Martin
+maintainer: Chris Martin, Julie Moronuki
+
+copyright: 2018 Typeclass Consulting, LLC
+license: MIT
+license-file: license.txt
+
+build-type: Simple
+tested-with: GHC==8.6.1
+
+extra-source-files:
+    changelog.md
+
+library
+    hs-source-dirs: library
+    default-language: Haskell2010
+
+    exposed-modules:
+        Skylighting.Extensions
+      , Skylighting.Extensions.GHCi
+      , Skylighting.Extensions.Haskell
+
+    build-depends:
+        base >=4.10 && <5
+      , containers
+      , skylighting
+      , skylighting-modding
+      , text