[shardling]

I think that requirement would conflict with some open source licenses -- they typically grant the right to redistribute and modify the source code in any way.

That would include stripping out everything but the icons and selling them.

So if the license requires all accompanying code/assets to be under similar licenses, that could prevent use of your icons. I think that's the case under the GPL? Not really sure anymore.

e: After doing a bit more reading, I believe I was wrong. As long as the icons aren't somehow compiled into the binary, there are no license problems.