open source

Hi, I am not sure if you are the right person for this question, but maybe you can redirect this email to someone else. I think you all are doing a terrific job on the php product. My question is, how do you make money? It is open-source, so you can't sell it. The reason for asking this is that i have created a collection of tools wich i could sell in the normal way, and make some money out of it, but i could also release it open-source and let many others work on it together with me to improve the product. But I have to eat.. so what's your secret? thanx in advance, Ruben