Hi all, winio is an I/O library for Windows using Windows API functions and has I/O completion port support. The main goal of this library is to support Simon Marlow's new Handle API once he has added that to GHC. The library also has a compatibility module for socket functions from the network-bytestring package. Because the library uses IOCP instead of select it is not limited to 1024 open sockets. Try for example the thread-ring program where each Haskell thread passes a UDP message around (Change the MaxUserPort field in HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters to 65534 to enable all ports). The winio package is available on Hackage. Notice that it uses a development version of the network package which is available at http://darcs.haskell.org/packages/network/. The library has not been tested much and should be considered experimental so please try it if you use Windows and notify me of any issue or corner case. Kind Regards, Felix