diff --git a/LICENSE b/LICENSE
new file mode 100644
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,22 @@
+Copyright (c) 2010 Richard Smith
+
+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/Setup.hs b/Setup.hs
new file mode 100644
--- /dev/null
+++ b/Setup.hs
@@ -0,0 +1,2 @@
+import Distribution.Simple
+main = defaultMain
diff --git a/System/Posix/Waitpid.hs b/System/Posix/Waitpid.hs
new file mode 100644
--- /dev/null
+++ b/System/Posix/Waitpid.hs
@@ -0,0 +1,32 @@
+{-# LANGUAGE ForeignFunctionInterface #-}
+{-# CFILES System/Posix/waitpid.c #-}
+
+module System.Posix.Waitpid where
+
+import Control.Monad
+import Data.List
+import Foreign
+import Foreign.C
+import System.Posix.Signals (Signal)
+import System.Posix.Types (CPid)
+
+foreign import ccall unsafe "SystemPosixWaitpid_waitpid" c_waitpid :: CPid -> Ptr CInt -> CInt -> IO CPid
+
+data Flag = NoHang | IncludeUntraced | IncludeContinued deriving Show
+data Status = Exited Int | Signaled Signal | Stopped Signal | Continued deriving (Show, Eq)
+
+waitpid :: CPid -> [Flag] -> IO (Maybe (CPid, Status))
+waitpid pid flags = alloca $ \status -> do
+  child <- throwErrnoIfMinus1 "waitpid" $ c_waitpid pid status options
+  stat <- peek status
+  return $ guard (child /= 0) >> return (child, extractStatus stat)
+ where
+  options = foldl' (.|.) 0 (map flagValue flags)
+  flagValue NoHang = 1
+  flagValue IncludeUntraced = 2
+  flagValue IncludeContinued = 4
+  extractStatus stat | stat < 0x10000 = Exited (fromIntegral stat)
+                     | stat < 0x20000 = Signaled (stat - 0x10000)
+                     | stat < 0x30000 = Stopped (stat - 0x20000)
+                     | stat == 0x30000 = Continued
+                     | otherwise = error $ "waitpid: unexpected status " ++ show stat
diff --git a/System/Posix/waitpid.c b/System/Posix/waitpid.c
new file mode 100644
--- /dev/null
+++ b/System/Posix/waitpid.c
@@ -0,0 +1,22 @@
+#include <sys/types.h>
+#include <sys/wait.h>
+
+pid_t SystemPosixWaitpid_waitpid(pid_t pid, int *result, int opts)
+{
+  int options = 0;
+  if (opts & 1) options |= WNOHANG;
+  if (opts & 2) options |= WUNTRACED;
+  if (opts & 4) options |= WCONTINUED;
+
+  int status = 0;
+  int retval = waitpid(pid, result ? &status : 0, options);
+  if (result)
+  {
+    if (WIFEXITED(status)) { *result = WEXITSTATUS(status); }
+    else if (WIFSIGNALED(status)) { *result = 0x10000 + WTERMSIG(status); }
+    else if (WIFSTOPPED(status)) { *result = 0x20000 + WSTOPSIG(status); }
+    else if (WIFCONTINUED(status)) { *result = 0x30000; }
+    else { *result = 0; }
+  }
+  return retval;
+}
diff --git a/posix-waitpid.cabal b/posix-waitpid.cabal
new file mode 100644
--- /dev/null
+++ b/posix-waitpid.cabal
@@ -0,0 +1,15 @@
+name:                posix-waitpid
+version:             0.1
+synopsis:            Low-level wrapping of POSIX waitpid(2).
+description:         A low-level wrapping of POSIX waitpid(2).
+category:            System
+license:             MIT
+license-file:        LICENSE
+author:              Richard Smith
+maintainer:          zygoloid@metafoo.co.uk
+build-type:          Simple
+cabal-version:       >= 1.6
+build-depends:       base == 4.*, unix
+c-sources:           System/Posix/waitpid.c
+exposed-modules:     System.Posix.Waitpid
+extensions:          ForeignFunctionInterface