The description you used on your lionite portfolio page sounded good: "Binpress is a marketplace for open-source code. Developers can sell and buy source code from each other, creating additional revenue for sellers and an inventory of certified, production ready source code for buyers. "

It's not perfect, but it at least mentions the key idea of 'marketplace for code'. This phrase (or something like it) should be used, even if you continue by saying that Binpress has open-source code too.