The recent open code drop of the F# compiler and library source has led to quite a lot of activity. One of the things has been the emergence of a MonoDevelop plugin for F#,
MonoDevelop is a cross-platform and open-source Integrated Development Environment. ...This web page describes an open-source project that implements MonoDevelop support for the F# language. The project is built on top of the F# compiler services. Currently, the aim is to provide consistent "user experience" for various platforms when creating small and medium F# projects (for example, when teaching F#).
The source for the project is currently hosted on GitHub.
Some related projects are:
Cross-platform downloads - get installer for Mac and packages for Linux
Cross-platform packages and samples - samples of using F# with cross-platform libraries such as OpenGL
F# PowerPack - additional open-source libraries and tools for F#