F Sharp

F# is a programming language developed at Microsoft and designed for the Microsoft-centric development environments currently centered on C# and .NET. It is intended to be a more modern and advanced language with multiple paradigms (functional, imperative, and object-oriented), and has an enthusiastic following but has not displaced C# in the more mainstream and less geeky parts of the software development field.

Language specs

 * Specs
 * F# 3.0 final spec

Links

 * F# Software Foundation
 * Wikipedia article
 * Try F# in your browser
 * Why your F# evangelism isn't working
 * What are the differences between in .fsx, .fsi and .fs file in F#?