Anyway here is a list of some of the best free scripts out there:
My favorite but it's for blog communities, add buddypress plugin and themes to it and it becomes a nice place for friends to meet and blog.
Cool easy to setup but have little support, themes and plugins if you have some php skills this core will be enough for you to start off.
Easy to use powerful script but I personal don't like it's navigation between pages.
Is the best in all free social networks it supports lot of plugins, video and music upload, video and audio chat and lot but it have ads, you need to pay to disable those or you need to get a nulled script which is illegal and can cause your site to get deleted by your host.
If you know other scripts please post a comment with a link to their site so we can grow this list.
Thanks and try the demos, try, plan before you start because seeing your social site empty feels so frustrating and it takes lots of time to populate these kind of sites.