diff --git a/.gitignore b/.gitignore
new file mode 100644
index 000000000..488c16c1c
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,6 @@
+pom.xml
+*jar
+/lib/
+/classes/
+.lein-failures
+.lein-deps-sum
diff --git a/README b/README
new file mode 100644
index 000000000..d0b0214c9
--- /dev/null
+++ b/README
@@ -0,0 +1,13 @@
+# typed-clojure
+
+FIXME: write description
+
+## Usage
+
+FIXME: write
+
+## License
+
+Copyright (C) 2011 FIXME
+
+Distributed under the Eclipse Public License, the same as Clojure.
diff --git a/project.clj b/project.clj
new file mode 100644
index 000000000..b54997645
--- /dev/null
+++ b/project.clj
@@ -0,0 +1,3 @@
+(defproject typed-clojure "1.0.0-SNAPSHOT"
+  :description "FIXME: write description"
+  :dependencies [[org.clojure/clojure "1.2.1"]])
\ No newline at end of file
diff --git a/src/typed_clojure/core.clj b/src/typed_clojure/core.clj
new file mode 100644
index 000000000..a8b80f063
--- /dev/null
+++ b/src/typed_clojure/core.clj
@@ -0,0 +1,68 @@
+(ns typed-clojure.core)
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Global type environment
+
+(defprotocol ITypeEnv
+  (extend-env! [this name type])
+  (get-env [this]))
+
+(deftype TypeEnv [env]
+  ITypeEnv
+  (get-env [this] env)
+  (extend-env! [this name type]
+    (swap! env assoc name type)))
+
+(def the-env (TypeEnv. (atom {})))
+
+(defn extend-env [name type]
+  (extend-env! the-env name type))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Type utilities
+
+(defn make-union [& types]
+  (vec types))
+
+(defmacro defnt [name & body]
+  (extend-env name (-> (meta name) :-))
+  `(defn ~name ~@body))
+
+(defn type-declaration [name type]
+  (extend-env name type))
+
+(defmacro make-type [name]
+  `(do
+     (deftype ~name [])
+     (new ~name)))
+
+(defmacro make-type-alias [name type]
+  `(make-type ~name))
+
+(deftype Function [sig])
+(defn make-Function [& types]
+  (Function. types))
+
+(deftype List [type])
+(defn make-Listof [sig]
+  (List. sig))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;; Primitive types
+
+;; TODO Work out proposition representation
+
+(make-type Any)
+(make-type None)
+
+(type-declaration + (make-Function Number Number Number))
+(type-declaration - (make-Function Number Number Number))
+
+;(make-pred-ty symbol? Symbol)
+
+(defnt ^{:- (make-Function Number Number)}
+  f
+  [x]
+  (if (number? x)
+    (+ x)
+    (- x)))
diff --git a/test/typed_clojure/test/core.clj b/test/typed_clojure/test/core.clj
new file mode 100644
index 000000000..3aa918f72
--- /dev/null
+++ b/test/typed_clojure/test/core.clj
@@ -0,0 +1,6 @@
+(ns typed-clojure.test.core
+  (:use [typed-clojure.core])
+  (:use [clojure.test]))
+
+(deftest replace-me ;; FIXME: write
+  (is false "No tests have been written."))