[Bungleau]

There should be an EULA or other licensing agreement with c# or C++. You should have had to agree to it when you installed the software, and you should be able to access it from within the compiler or development tools.

Basically, however, you should be able to sell the tools you develop. You may need (or want) to provide them as compiled code instead of source code; that way, it's harder (but not impossible) for someone to get a copy without paying you for it.