Known .Net Languages

.NET IL Assembler	Serge Lidin's book - .NET IL Assembler
Ada	Ada
APL	Dyalog APL
AsmL	AsmL is the Abstract State Machine Language for .NET
CAML	Microsoft Research F#
Cobol	Fujitsu Cobol
Delphi	Borland Delphi
Forth	Delta Forth
Eiffel	Interactive Software Engineering Eiffel for .NET
Fortran	Lahey/Fujitsu Fortran for .NET
Fortran	Salford FTN95 for Microsoft .NET
Haskell	Hugs98 for .NET
Lisp	DotLisp - Lisp dialect for .NET
Lua	Lua.NET embedded scripting language
Mercury	Melbourne University Mercury Project
Mixal	Mixal for .NET
ML	Standard ML from Microsoft Research
Mondrian	Mondrian for .NET
Nemerle	hybrid functional/OO language for .NET
Oberon	ETH Active Oberon for .net
Pascal	Queensland University Component Pascal
Perl	ActiveState Perl Dev Kit with PerlNET
PHP	PHP_Sharp compiler for .NET
Prolog	Compiles Prolog to C#
Python	ActiveState Python for .NET Research
RPG	ASNA Visual RPG
Ruby	NetRuby interpreter
Ruby	Ruby/.NET Bridge
Scheme	Tachy (Scheme-like) language
Scheme	Indiana University Scheme.NET
Smalltalk	SmallScript from SmallScript LLC
Smalltalk	#Smalltalk compiler

Source: GotDotNet.com