F# is a general purpose programming language for .NET first implemented by Dr. Don Syme at Microsoft Research in Cambridge.
Some people say that it is the easiest and most flexible .NET language.
It can also be called "Visual F#".
F# compiler and most of its tools are open source, even if there is a F# team of engineers at Microsoft.
F# is not purely functional and instead mixes ideas from Functional Programming, Object Oriented Programming as well as Procedural Programming paradigms.
This is very advantageous in that pure functional programming is not the best approach to many type of general applications alot of developers make.
F# allows you to choose the best paradigm to use for your project.
F# is a strongly typed programming language. However, like many modern languages, it supports type inference, which is the ability of the compiler to automatically infer the types of variables from the supplied data.
F# also integrates with the .NET Framework Base Class Library(BCL), just like it's sisters C# and VB.NET.
F# is powerful in that it embraces .NET philosophy fully and allows users to do everything that the other .NET languages can do.
F# compiler can compile code for all the CLI(Common Language Infrastructure). F# is furthermore just as cross platform as the CLI will be.
Here's the hello world program in F#:
let helloworld = "Hello World!" // print the results let main() = printfn "%A" helloworld // call the main function main()