Multi-lingual projects in Visual Studio
Would anyone know if there are plans or extensions to Visual Studio to allow for multi-lingual projects?
While the .NET platform is truly polyglot, Visual Studio project are stubbornly monoglot which means that all the work that goes into tooling C# and VB is unusable from newer languages like F# and IronPython.
PEX is an example of a great extension to Visual Studio that simply doesn't work in F#.
Wasn't there a module system built into .NET specifically to enable ployglot compilation?
I work at Microsoft on the F# team and .NET Libraries like PEX should be fully interoperable with F# modulo bugs, so if you are blocked by something please send the issue to email@example.com.
It is possible to produce multi-language assemblies in .NET, using a concept called netmodules: http://blogs.msdn.com/junfeng/archive/2005/02/12/371683.aspx. Unfortunately I don't know if F# supports this (I doubt it.)
As for getting tooling support for polyglot development, there are currently no plans to enable that within Visual Studio. However, please consider providing mentioning this on http://connect.microsoft.com/VisualStudio. The people who drive features for future releases take feedback on that site into consideration, especially if it gets a lot of traction in the .NET community.
But for the time being I recommend you use F# for what it is good at - algorithmic development, exploring data, etc. And use C#/VB for the presentation layer.