diff --git a/CHANGELOG.md b/CHANGELOG.md
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--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,11 @@
+# Changelog for `ftcqueue`
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to the
+[Haskell Package Versioning Policy](https://pvp.haskell.org/).
+
+## Unreleased
+
+## 0.1.0.0 - YYYY-MM-DD
diff --git a/LICENSE b/LICENSE
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--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,26 @@
+Copyright 2025 Yoshikuni Jujo
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1.  Redistributions of source code must retain the above copyright notice, this
+    list of conditions and the following disclaimer.
+
+2.  Redistributions in binary form must reproduce the above copyright notice,
+    this list of conditions and the following disclaimer in the documentation
+    and/or other materials provided with the distribution.
+
+3.  Neither the name of the copyright holder nor the names of its contributors
+    may be used to endorse or promote products derived from this software
+    without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
+ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/README.md b/README.md
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--- /dev/null
+++ b/README.md
@@ -0,0 +1,32 @@
+# ftcqueue
+
+## See
+
+https://okmij.org/ftp/Haskell/zseq.pdf
+
+## Sample Code
+
+```Haskell
+module Main (main) where
+
+import Data.Time
+import Data.FTCQueue
+
+import Lib
+
+main :: IO ()
+main = foo `apply` ()
+
+foo :: Q IO () ()
+foo = singleton (const getLine) |> addTime |> putStrLn
+
+addTime :: String -> IO String
+addTime msg = do
+	ct <- getCurrentTime
+	pure $ msg ++ " (" ++ show ct ++ ")"
+
+apply :: Monad t => Q t a b -> a -> t b
+q `apply` x = case viewl q of
+	One f -> f x
+	f :| q' -> f x >>= (q' `apply`)
+```
diff --git a/Setup.hs b/Setup.hs
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--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/ftcqueue.cabal b/ftcqueue.cabal
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--- /dev/null
+++ b/ftcqueue.cabal
@@ -0,0 +1,53 @@
+cabal-version: 2.2
+
+-- This file has been generated from package.yaml by hpack version 0.38.1.
+--
+-- see: https://github.com/sol/hpack
+
+name:           ftcqueue
+version:        0.1.0.0
+description:    Please see the README on GitHub at <https://github.com/YoshikuniJujo/ftcqueue#readme>
+homepage:       https://github.com/YoshikuniJujo/ftcqueue#readme
+bug-reports:    https://github.com/YoshikuniJujo/ftcqueue/issues
+author:         Yoshikuni Jujo
+maintainer:     yoshikuni.jujo@gmail.com
+copyright:      (c) 2025 Yoshikuni Jujo
+license:        BSD-3-Clause
+license-file:   LICENSE
+build-type:     Simple
+extra-source-files:
+    README.md
+    CHANGELOG.md
+
+source-repository head
+  type: git
+  location: https://github.com/YoshikuniJujo/ftcqueue
+
+library
+  exposed-modules:
+      Data.FTCQueue
+  other-modules:
+      Paths_ftcqueue
+  autogen-modules:
+      Paths_ftcqueue
+  hs-source-dirs:
+      src
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints
+  build-depends:
+      base >=4.7 && <5
+  default-language: Haskell2010
+
+test-suite ftcqueue-test
+  type: exitcode-stdio-1.0
+  main-is: Spec.hs
+  other-modules:
+      Paths_ftcqueue
+  autogen-modules:
+      Paths_ftcqueue
+  hs-source-dirs:
+      test
+  ghc-options: -Wall -Wcompat -Widentities -Wincomplete-record-updates -Wincomplete-uni-patterns -Wmissing-export-lists -Wmissing-home-modules -Wpartial-fields -Wredundant-constraints -threaded -rtsopts -with-rtsopts=-N
+  build-depends:
+      base >=4.7 && <5
+    , ftcqueue
+  default-language: Haskell2010
diff --git a/src/Data/FTCQueue.hs b/src/Data/FTCQueue.hs
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--- /dev/null
+++ b/src/Data/FTCQueue.hs
@@ -0,0 +1,42 @@
+{-# LANGUAGE ExistentialQuantification #-}
+{-# OPTIONS_GHC -Wall -fno-warn-tabs #-}
+
+module Data.FTCQueue (
+
+	-- * Q TYPE
+
+	Q,
+
+	-- * CONSTRUCTION
+
+	singleton, (|>), (><),
+
+	-- * VIEW
+
+	viewl, ViewL(..)
+
+	) where
+
+data Q t a b = Leaf (a -> t b) | forall x . Node !(Q t a x) !(Q t x b)
+
+singleton :: (a -> t b) -> Q t a b
+singleton = Leaf
+
+infixl 5 |>
+infixr 5 ><, :|
+
+(|>) :: Q t a b -> (b -> t c) -> Q t a c
+(|>) = (. Leaf) . Node
+
+(><) :: Q t a b -> Q t b c -> Q t a c
+(><) = Node
+
+data ViewL t a b = One (a -> t b) | forall x . (a -> t x) :| !(Q t x b)
+
+viewl :: Q t a b -> ViewL t a b
+viewl (Leaf f) = One f
+viewl (Node l0 r0) = go l0 r0
+	where
+	go :: Q t a x -> Q t x b -> ViewL t a b
+	go (Leaf f) r = f :| r
+	go (Node ll lr) r = go ll (Node lr r)
diff --git a/test/Spec.hs b/test/Spec.hs
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--- /dev/null
+++ b/test/Spec.hs
@@ -0,0 +1,2 @@
+main :: IO ()
+main = putStrLn "Test suite not yet implemented"