well besides the Microsoft languaget here are the languages that .net now supports with more to come

COBOL for Microsoft .NET.
Perl for Microsoft .NET.
Eiffel for Microsoft .NET.
Python for Microsoft .NET.
Pascal for Microsoft .NET.
Mercury for Microsoft .NET.
Mondrian for Microsoft .NET.
Oberon for Microsoft .NET.
Salford FTN95 (Fortran) for Microsoft .NET.
SmallTalk for Microsoft .NET.
Standard ML for Microsoft .NET.
Dyalog APL for Microsoft .NET.

other companies are working on .net plugins for their languages