Open Source Tool which Convert Source Code from one Language to other

Question

Is there any tool which converts the source code in one language to other...

Answer 1

The only tool I know of that has anything like this is LLVM which provides a C backend, i.e. it should be able generate C code from any language for which there is an LLVM front-end.

Answer 2

You can look at TXL, a program transformation tool that has been used to implement language-to-language translators.

EDIT: (after OP clarified his question slightly in a comment) You aren't very clear about the translations direction: Java-to-C# or C#-to-Java. However, this SO thread seems to address both to some degree: http://stackoverflow.com/questions/78811/is-there-an-effective-tool-to-convert-c-to-java (the link is really to convert-c#-to-java; SO apparantly can't put a # in a link).