BuddyPress is completely free and open source. Unlike hosted services, BuddyPress allows you to stay in control of your site and create a totally customized, unique experience.

I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use. (Galileo Galilei)

Each problem that I solved became a rule which served afterwards to solve other problems. (Rene Descartes, Discours de la Methode)