We've posted a minor update to version 1.9.4 (called 1.9.4.19). The change notice is in the README and below. There are three fixes/changes in this release

There was a glitch that prevented F# version 1.9.4.17 programs working well on Mono. A workarounds was mentioned here http://laurent.le-brun.eu/site/index.php/2008/06/05/36-how-to-use-fsharp-1-9-4-17-on-mono, though this workaround should now no longer be needed.

WebRequest.GetResponseAsync has been removed from FSharp.Core.dll, to help allow F# programs to be used on SIlverlight and other platforms where this method either doesn’t exist or is in a non-standard place. See the release notes if you need this method (for example, it is needed for some examples in Expert F#)

We have fixed a compiler problem related to .NET 3.5 SP1 Beta (“strange entry in exported types table”)

http://research.microsoft.com/research/downloads/Details/7ac148a7-149b-4056-aa06-1e6754efd36f/Details.aspx (MSI)
http://research.microsoft.com/research/downloads/Details/6f48a466-4294-4973-9e15-25e0ddff422f/Details.aspx (ZIP)

F# On Mono

The Mono 2.0 profile for F# is now used. On Mono the F# compiler is now invoked using mono bin\fscp.exe. See the notes above for details of this. NOTE: compiler startup times may be reduced on Mono because the Mono 1.9 doesn't support 'Ahead of Time Compilation' for its 2.0 profile. This won't normally be a problem if you're only using F# Interactive (fsi.exe). If it is a problem then see the instructions above for using the .NET 1.x profile compiler.

Library

WebRequest.GetResponseAsync now removed from the F# library since its use of a System.Net method makes FSharp.Core.dll unusable on some .NET platforms. To use this method use:

        type System.Net.WebRequest with
            member x.GetResponseAsync() =
                Async.BuildPrimitive(x.BeginGetResponse, x.EndGetResponse)

Bugs fixed

2033 F# Compiler doesn't work with type forwarders found in .NET Framework 3.5 SP 1 Beta1