F# February 2010 CTP provides all the tools and resources needed to develop applications with the F# programming language. F# is a functional programming language for the .NET Framework. It combines the succinct, expressive and compositional style of functional programming with the runtime, libraries, interoperability, and object model of .NET. F# is well suited to a spectrum of development tasks - from interactive, explorative scripting to component and large-scale software development. The CTP release of F# provides further support for explorative development using F#, as well as improved Visual Studio integration to enable large-scale, tool-based software development.
Download: F# February 2010 CTP