The icons themselves are the Silk Icon Set, which is under the Creative Commons Attribution 2.5 License. So you can do whatever you want with them, but you have to credit the original author in the readme or whatever.

ParticleShop " It's like Photoshop, get it? No? Aw. " The not at all waited for and utterly mediocre pet project of mine. It's just a run of the mill ParticleSystem editor, really more of a learning exercise than anything else. Hopefully when it's finished, I'll actually have a tool that'...