Yes, that's what I meant.

Most -- nearly all -- major open-source projects written in C# (or other .NET languages) are permissively licensed. Yes, that means people could just grab the code and use it in their own closed-source projects without giving back; but, as far as I've seen, most devs are happy to contribute back to the projects they use in whatever way they can.

It's not just commercial use. Non-permissive open source licenses are also frequently incompatible with one another [1].

[1] http://www.gnu.org/licenses/license-list.html#GPLIncompatibl...