diff --git a/LICENSE b/LICENSE
--- a/LICENSE
+++ b/LICENSE
@@ -1,4 +1,4 @@
-Copyright (c) 2009-2013, Jinjing Wang
+Copyright (c) 2009-2016, Jinjing Wang
 
 All rights reserved.
 
diff --git a/Nemesis b/Nemesis
deleted file mode 100644
--- a/Nemesis
+++ /dev/null
@@ -1,76 +0,0 @@
-import System.Nemesis.Env
-import Air.Env ((-))
-import Prelude hiding ((-))
-
-main = run nemesis
-
-nemesis = do
-  
-  clean
-    [ "**/*.hi"
-    , "**/*.o"
-    , "manifest"
-    , "main"
-    , "nemesis-tmp.*"
-    , "dist"
-    ]
-  
-
-  desc "prepare cabal dist"
-  task "dist" - do
-    sh "cabal clean"
-    sh "cabal configure"
-    sh "cabal sdist"
-
-
-  desc "put all .hs files in manifest"
-  task "manifest" - do
-    sh "find . | grep 'hs$' > manifest"
-
-
-  desc "start console"
-  task "i" (sh "ghci -isrc src/System/Nemesis/DSL.hs")
-  
-
-  task "runner" (sh "ghci -isrc src/System/Nemesis/Runner.hs")
-
-  desc "show sloc"
-  task "stat" - do
-    sh "cloc -match-f=hs$ --quiet ."
-
-  -- test for readme
-
-  -- desc is optional, it gives some description to the following task
-  desc "Hunter attack macro"
-  
-  -- syntax: task "keyword: dependencies" io-action
-  task "attack: pet-attack auto-attack" (putStrLn "attack macro done!")
-
-  desc "Pet attack"
-  task "pet-attack: mark" - do
-    sh "echo 'pet attack'"
-
-  desc "Hunter's mark"
-  task "mark" - do
-    sh "echo \"casting hunter's mark\""
-  
-  desc "Auto attack"
-  task "auto-attack" - do
-    sh "echo 'auto shoot'"
-    
-    
-    
-  namespace "eat" - do
-
-    task "bread: salad" - putStrLn "eating bread"
-    task "salad: /drink/coke" - putStrLn "nice salad"
-
-
-  namespace "drink" - do
-
-    task "coke" - putStrLn "drinking coke"
-    
-  
-  desc "test"
-  task "test" - do
-    sh "runghc test/N1.hs"
diff --git a/changelog.md b/changelog.md
--- a/changelog.md
+++ b/changelog.md
@@ -1,3 +1,8 @@
+2016.3.19
+---------
+
+* remove `air` dependency
+
 2013.6.16
 ---------
 
diff --git a/nemesis.cabal b/nemesis.cabal
--- a/nemesis.cabal
+++ b/nemesis.cabal
@@ -1,46 +1,52 @@
-Name:                 nemesis
-Version:              2015.5.4
-Build-type:           Simple
-Synopsis:             a task management tool for Haskell
-Description:          Organize common shell tasks into a meaningful tree like structure with dependency tracking
+name:                 nemesis
+category:             Tools
+version:              2016.3.19
+cabal-version:        >= 1.6
 
-License:              BSD3
-License-file:         LICENSE
-Author:               Jinjing Wang
-Maintainer:           Jinjing Wang <nfjinjing@gmail.com>
-Cabal-version:        >= 1.6
-category:             Web
+license:              BSD3
+license-file:         LICENSE
+
+author:               Jinjing Wang
+maintainer:           Jinjing Wang <nfjinjing@gmail.com>
+
+build-type:           Simple
+tested-with:          GHC == 7.10.3
+
+synopsis:             a task management tool for Haskell
+description:          Organize common shell tasks into a meaningful tree like structure with dependency tracking
+
 homepage:             http://github.com/nfjinjing/nemesis
 
-data-files:           readme.md
+extra-doc-files:      readme.md
                     , changelog.md
                     , known-issues.md
-                    , Nemesis
-                    , test/N1.hs
-                    , test/N2.hs
-                    , test/N3.hs
 
 source-repository head
   type: git
   location: https://github.com/nfjinjing/nemesis.git
 
 library
-  ghc-options: -Wall
-  build-depends:      base >= 4 && < 100
-                    , time
-                    , mtl
-                    , process
-                    , containers
-                    , air >= 2014.5.19
-                    , air-th
-                    , dlist
+  ghc-options:      -Wall -fno-warn-unused-do-bind
+  build-depends:
+                      base > 4 && <= 6
                     , Glob
+                    , containers
                     , directory
+                    , dlist
+                    , lens
+                    , mtl
+                    , process
+                    , time
 
-  hs-source-dirs: src/
+                    -- testing
+                    -- , foreign-store >= 0.2
+                    -- , air
+
+  hs-source-dirs:     src/
   exposed-modules:
                       System.Nemesis
                       System.Nemesis.DSL
                       System.Nemesis.Env
-  other-modules:
-                      System.Nemesis.Util
+                      System.Nemesis.Driver
+                      System.Nemesis.Type
+                      System.Nemesis.Utils
diff --git a/readme.md b/readme.md
--- a/readme.md
+++ b/readme.md
@@ -4,7 +4,7 @@
 Demo
 ----
   
-    import System.Nemesis.Env
+    import System.Nemesis
 
     main = run $ do
 
@@ -36,8 +36,8 @@
 
 Create a file named `Nemesis`
 
-    import System.Nemesis.Env
-    import Air.Env ((-))
+    import System.Nemesis
+    import System.Nemesis.Utils ((-))
     import Prelude hiding ((-))
     
     main = run - do
@@ -80,8 +80,8 @@
 
 Create namespaces for tasks with the keyword `namespace`
     
-    import System.Nemesis.Env
-    import Air.Env ((-))
+    import System.Nemesis
+    import System.Nemesis.Utils ((-))
     import Prelude hiding ((-))
 
     main = run - do
diff --git a/src/System/Nemesis.hs b/src/System/Nemesis.hs
--- a/src/System/Nemesis.hs
+++ b/src/System/Nemesis.hs
@@ -1,116 +1,16 @@
 {-# LANGUAGE NamedFieldPuns #-}
 {-# LANGUAGE TemplateHaskell #-}
 
-module System.Nemesis where
-
-import Prelude ()
-import Air.Env hiding (lookup)
-import Air.TH hiding (get)
-import Control.Monad.State hiding (State, join)
-import Data.List (sort)
-import Data.Map (Map, insert, lookup, elems)
-import System.Environment
-import Text.Printf
-
-newtype ShowIO = ShowIO {unShowIO :: IO () }
-
-instance Show ShowIO where
-  show _ = "IO"
-
-instance Default ShowIO where
-  def = ShowIO (return ())
-
-data Task = Task
-  {
-    name :: String
-  , action :: ShowIO
-  , deps :: [String]
-  , description :: Maybe String
-  , namespace :: [String]
-  }
-  deriving (Show)
-
-mkDefault ''Task
-
-data Nemesis = Nemesis
-  {
-    tasks :: Map String Task
-  , target :: String
-  , current_desc :: Maybe String
-  , current_namespace :: [String]
-  }
-  deriving (Show)
-
-mkDefault ''Nemesis
-
-full_name :: Task -> String
-full_name t = (t.name : t.namespace).reverse.join "/"
-
-display_name :: Task -> String
-display_name t = (t.name : t.namespace).reverse.map (printf "%-10s") .join " "
-
-show_task :: Task -> String
-show_task = show_with_ljust 44
-
-instance Eq Task where
-  a == b = a.name == b.name
-
-instance Ord Task where
-  compare = compare_by full_name
-
-type Unit = StateT Nemesis IO ()
-
-show_with_ljust :: Int -> Task -> String
-show_with_ljust n task=
-  case task.description of
-    Nothing -> task.full_name
-    Just x -> task.full_name.ljust n ' ' + x
-
-run :: Unit -> IO ()
-run unit = do
-  args <- getArgs
-  case args of
-    [] -> help
-    _target:_ -> execStateT unit def {target = _target} >>= run_nemesis
-
-  where
-    help = execStateT unit def >>= list_task
-    list_task n = do
-      let _tasks = n.tasks.elems
-
-          _task_len = _tasks.map (full_name > length) .maximum + 5
-
-      br
-      n.tasks.elems.sort.map (show_with_ljust _task_len) .mapM_ putStrLn
-      br
-    br = puts ""
+module System.Nemesis
 
-insert_task :: Task -> Unit
-insert_task t = do
-  n <- get
-  let description = n.current_desc
-      namespace   = n.current_namespace
-      deps'       = t.deps.map (with_current namespace)
-      task        = t {deps = deps', description, namespace}
-      tasks'      = n.tasks.insert (task.full_name) task
+(
 
-  put n {tasks = tasks', current_desc = Nothing}
-  where
-    with_current namespace x
-      | x.starts_with "/" = x.tail
-      | otherwise = (x : namespace).reverse.join "/"
+  module System.Nemesis.DSL
+, module System.Nemesis.Driver
 
-run_nemesis :: Nemesis -> IO ()
-run_nemesis n = run' (n.target)
-  where
-    run' :: String -> IO ()
-    run' s = case (n.tasks.lookup s) of
-      Nothing -> bye
-      Just x -> run_task x
-      where
-        bye = do
-          printf "%s does not exist!" s
+)
 
+where
 
-    run_task :: Task -> IO ()
-    run_task t = t.deps.mapM_ run' >> t.action.unShowIO
+import System.Nemesis.DSL
+import System.Nemesis.Driver (run)
diff --git a/src/System/Nemesis/DSL.hs b/src/System/Nemesis/DSL.hs
--- a/src/System/Nemesis/DSL.hs
+++ b/src/System/Nemesis/DSL.hs
@@ -2,55 +2,53 @@
 
 module System.Nemesis.DSL where
 
-import Control.Monad.State hiding (State, join)
-import Data.List (nub, sort)
-import Prelude ()
-import Air.Env
-import System.Exit
-import System.Process
-import System.Directory
-import System.FilePath.Glob
-import System.Nemesis
-import System.Nemesis.Util
-import Text.Printf
+import           Control.Arrow
+import           Control.Lens
+import           Control.Monad.State   hiding (State)
+import           Data.List
+import           Prelude               hiding ((-))
+import           System.Directory
+import           System.Exit
+import           System.FilePath.Glob
+import           System.Nemesis.Driver
+import           System.Nemesis.Type
+import           System.Nemesis.Utils
+import           System.Process
+import           Text.Printf
 
 desc :: String -> Unit
-desc s = do
-  n <- get
-  put n {current_desc = Just s}
+desc = (currentDesc .=) . Just
 
 task :: String -> IO () -> Unit
-task s action =
-  if s.has ':'
+task s aAction =
+  if ':' `elem` s
     then
-      let h = s.takeWhile (/= ':')
-          t = s.dropWhile (/= ':') .tail
+      let h = s & takeWhile (/= ':')
+          t = s & dropWhile (/= ':') & tail
       in
-      task' (h.strip) (t.words)
+      task' (strip h ) (words t)
     else
       task' s []
   where
-    task' name deps = insert_task def {name, deps, action = ShowIO action}
-    strip = dropWhile (== ' ') > reverse > dropWhile (== ' ') > reverse
+    task' _name _deps = insertTask -
+                      emptyTask
+                        & name .~ _name
+                        & deps .~ _deps
+                        & action .~ ShowIO aAction
+    strip = dropWhile (== ' ') >>> reverse >>> dropWhile (== ' ') >>> reverse
 
 namespace :: String -> Unit -> Unit
-namespace name unit = do
-  push name
-  unit
+namespace aName aUnit = do
+  push aName
+  aUnit
   pop
 
   where
     push :: String -> Unit
-    push s = do
-      n <- get
-      let current_namespace' = s : n.current_namespace
-      put n {current_namespace = current_namespace'}
+    push = (currentNamespace %=) . (:)
 
     pop :: Unit
-    pop = do
-      n <- get
-      let current_namespace' = n.current_namespace.tail
-      put n {current_namespace = current_namespace'}
+    pop = (currentNamespace %= tail)
 
 sh :: String -> IO ()
 sh s = do
@@ -58,7 +56,7 @@
   case status of
     ExitSuccess -> return ()
     ExitFailure code -> do
-      puts - printf "%s failed with status code: %s" s (show code)
+      putStrLn - printf "%s failed with status code: %s" s (show code)
       exitWith status
 
 
@@ -66,11 +64,12 @@
 clean xs = do
   desc "Remove any temporary products."
   task "clean" - do
-    paths <- globDir (xs.map compile) "." ^ fst ^ concat ^ nub ^ sort ^ reverse
-    mapM_ rm_any paths
+    paths <- globDir (xs & map compile) "." <&> fst <&> concat <&> nub <&> sort <&> reverse
+    mapM_ rmAny paths
     where
-      rm_any s = do
-        file_exist <- doesFileExist s
-        when file_exist - rm s
-        dir_exist <- doesDirectoryExist s
-        when dir_exist - rm_rf s
+      rmAny s = do
+        _fileExist <- doesFileExist s
+        when _fileExist - removeFile s
+        _dirExist <- doesDirectoryExist s
+        when _dirExist - removeDirectoryRecursive s
+
diff --git a/src/System/Nemesis/Driver.hs b/src/System/Nemesis/Driver.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Nemesis/Driver.hs
@@ -0,0 +1,86 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+module System.Nemesis.Driver where
+
+import           Control.Arrow        ((>>>))
+import           Control.Lens
+import           Control.Monad.State  hiding (State, join)
+import           Data.List
+import qualified Data.Map             as Map
+import           Data.Monoid
+import           Prelude              hiding ((-))
+import           System.Environment
+import           System.Nemesis.Type
+import           System.Nemesis.Utils
+import           Text.Printf
+
+
+
+displayName :: Task -> String
+displayName t = (t ^. name : t ^. namespace) & reverse & map (printf "%-10s") & intercalate " "
+
+showTask :: Task -> String
+showTask = showWithLeftJust 44
+
+
+showWithLeftJust :: Int -> Task -> String
+showWithLeftJust n task =
+  case task ^. description of
+    Nothing -> fullName task
+    Just x -> fullName task & ljust n ' ' & (<> x)
+
+run :: Unit -> IO ()
+run unit = do
+  args <- getArgs
+  case args of
+    [] -> help
+    _target:_ -> execStateT unit (emptyNemesis & target .~ _target) >>= runNemesis
+
+  where
+    help = execStateT unit (emptyNemesis) >>= list_task
+    list_task n = do
+      let _tasks = n ^. tasks & Map.elems
+
+          _task_len = _tasks & map (fullName >>> length) & maximum & (+ 5)
+
+      br
+      n ^. tasks & Map.elems & sort & map (showWithLeftJust _task_len) & traverse putStrLn
+      br
+    br = putStrLn ""
+
+insertTask :: Task -> Unit
+insertTask t = do
+  n <- get
+  let _description = n ^. currentDesc
+      _namespace   = n ^. currentNamespace
+      _deps       = t ^. deps & map (withCurrent _namespace)
+      _task        = t
+                      & deps .~ _deps
+                      & description .~ _description
+                      & namespace .~ _namespace
+      _tasks      = n ^. tasks & Map.insert (_task & fullName) _task
+
+  put - n
+          & tasks .~ _tasks
+          & currentDesc .~ mempty
+  where
+    withCurrent aNamespace x
+      | "/" `isPrefixOf` x = tail x
+      | otherwise = (x : aNamespace) & reverse & intercalate "/"
+
+runNemesis :: Nemesis -> IO ()
+runNemesis n = run' (n ^. target)
+  where
+    run' :: String -> IO ()
+    run' s = case n ^. (tasks . at s) of
+      Nothing -> bye
+      Just x -> run_task x
+      where
+        bye = do
+          printf "%s does not exist!" s
+
+
+    run_task :: Task -> IO ()
+    run_task t = do
+      t ^. deps & traverse run'
+      t ^. action & unShowIO
diff --git a/src/System/Nemesis/Env.hs b/src/System/Nemesis/Env.hs
--- a/src/System/Nemesis/Env.hs
+++ b/src/System/Nemesis/Env.hs
@@ -1,4 +1,4 @@
-module System.Nemesis.Env 
+module System.Nemesis.Env
 
 (
 
@@ -8,7 +8,6 @@
 )
 
 where
-  
 
-import System.Nemesis.DSL
-import System.Nemesis (run)
+import           System.Nemesis     (run)
+import           System.Nemesis.DSL
diff --git a/src/System/Nemesis/Type.hs b/src/System/Nemesis/Type.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Nemesis/Type.hs
@@ -0,0 +1,55 @@
+{-# LANGUAGE TemplateHaskell #-}
+
+module System.Nemesis.Type where
+
+import           Control.Lens
+import           Control.Monad.State hiding (State, join)
+import           Data.Function
+import           Data.List
+import           Data.Map            (Map)
+import           Prelude             hiding ((-))
+
+newtype ShowIO = ShowIO {unShowIO :: IO () }
+
+instance Show ShowIO where
+  show _ = "IO"
+
+data Task = Task
+  {
+    _name        :: String
+  , _action      :: ShowIO
+  , _deps        :: [String]
+  , _description :: Maybe String
+  , _namespace   :: [String]
+  }
+  deriving (Show)
+
+emptyTask :: Task
+emptyTask = Task mempty (ShowIO (pure ())) mempty mempty mempty
+
+makeLenses ''Task
+
+data Nemesis = Nemesis
+  {
+    _tasks            :: Map String Task
+  , _target           :: String
+  , _currentDesc      :: Maybe String
+  , _currentNamespace :: [String]
+  }
+  deriving (Show)
+
+emptyNemesis :: Nemesis
+emptyNemesis = Nemesis mempty mempty mempty mempty
+
+makeLenses ''Nemesis
+
+instance Eq Task where
+  (==) = (==) `on` (view name)
+
+fullName :: Task -> String
+fullName t = intercalate "/" . reverse $ (t ^. name : t ^. namespace)
+
+instance Ord Task where
+  compare = compare `on` fullName
+
+type Unit = StateT Nemesis IO ()
diff --git a/src/System/Nemesis/Util.hs b/src/System/Nemesis/Util.hs
deleted file mode 100644
--- a/src/System/Nemesis/Util.hs
+++ /dev/null
@@ -1,21 +0,0 @@
-{-# LANGUAGE NoMonomorphismRestriction #-}
-
-module System.Nemesis.Util (
-    ls
-  , rm
-  , rm_rf
-) where
-
-import System.Directory
-import Air.Env
-import Prelude ()
-import Data.List ((\\))
-
-ls :: String -> IO [String]
-ls s = getDirectoryContents s ^ (\\ [".", ".."])
-
-rm :: String -> IO ()
-rm = removeFile
-
-rm_rf :: String -> IO ()
-rm_rf = removeDirectoryRecursive
diff --git a/src/System/Nemesis/Utils.hs b/src/System/Nemesis/Utils.hs
new file mode 100644
--- /dev/null
+++ b/src/System/Nemesis/Utils.hs
@@ -0,0 +1,15 @@
+{-# LANGUAGE OverloadedStrings #-}
+
+module System.Nemesis.Utils where
+
+import           Prelude          hiding ((-))
+
+infixr 0 -
+{-# INLINE (-) #-}
+(-) :: (a -> b) -> a -> b
+f - x = f x
+
+ljust :: Int -> a -> [a] -> [a]
+ljust n x xs
+  | n < length xs = xs
+  | otherwise     = take n (xs ++ replicate n x)
diff --git a/test/N1.hs b/test/N1.hs
deleted file mode 100644
--- a/test/N1.hs
+++ /dev/null
@@ -1,19 +0,0 @@
-import System.Nemesis.Env
-
-main = run $ do
-
-  clean
-    [ "**/*.hi"
-    , "**/*.o"
-    , "manifest"
-    ]
-    
-  task "dist" $ do
-    sh "cabal clean"
-    sh "cabal configure"
-    sh "cabal sdist"
-
-  task "i" (sh "ghci -isrc src/System/Nemesis.hs")
-
-  task "manifest" $ do
-    sh "find . | grep 'hs$' > manifest"
diff --git a/test/N2.hs b/test/N2.hs
deleted file mode 100644
--- a/test/N2.hs
+++ /dev/null
@@ -1,22 +0,0 @@
-import System.Nemesis.Env
-import Air.Env ((-))
-import Prelude hiding ((-))
-
-main = run - do
-
-  -- desc is optional, it gives some description to the task
-  -- task syntax: task "keyword: space seperated dependencies" io-action
-  desc "Hunter attack macro"
-  task "attack: pet-attack auto-attack" (putStrLn "attack macro done!")
-
-  desc "Pet attack"
-  task "pet-attack: mark" - do
-    sh "echo 'pet attack'"
-
-  desc "Hunter's mark"
-  task "mark" - do
-    sh "echo \"casting hunter's mark\""
-
-  desc "Auto attack"
-  task "auto-attack" - do
-    sh "echo 'auto shoot'"
diff --git a/test/N3.hs b/test/N3.hs
deleted file mode 100644
--- a/test/N3.hs
+++ /dev/null
@@ -1,15 +0,0 @@
-import System.Nemesis.Env
-import Air.Env ((-))
-import Prelude hiding ((-))
-
-main = run - do
-
-  namespace "eat" - do
-
-    task "bread: salad" - putStrLn "eating bread"
-    task "salad: /drink/coke" - putStrLn "eating salad"
-
-
-  namespace "drink" - do
-
-    task "coke" - putStrLn "drinking coke"