Spot on.

The license terms mean that the icon set cannot be used in open source projects intended for redistribution. Your call, of course, just pointing it out.

It might be better to use a more standard license, maybe Apache or BSD with an extra clause prohibiting "sale in whole apart from use in a larger software distribution." IANAL but it might hold up better and be less confusing.

Otherwise, obviously really great work and very generous. Thanks.

@davidw - that is meant to refer to not selling or redistributing the icon pack as a whole - you are more than welcome to use it in any open source redistributed work.

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.

It sounds like you want

http://www.tldrlegal.com/license/CC-NC

No, this differs from CC-NC in that you can use them in a commercial work, you just can't sell them on their own. Using CC-NC would prevent users from bundling these into a commercial product whatsoever.

In that case...

Public Domain and CCZero would be a very efficient way to quiet people's fears about what they can't do with this icon set, without alarming them that they need Legal Advice to build their app. You've tried to trim down the restrictions to almost nothing, but we have an established protocol to encompass all uses. Why not go all the way?