BuddyPress

BuddyPress adds social-network features to a WordPress.org-powered site, including user profiles, activity streams, user groups, and more. It is for people who run WordPress.org sites and want to take them beyond blogs. The plugin adds profiles for users. It also adds streams for activity and groups for users. All of these social-network features run on the WordPress.org-powered site. They let the owner expand the site's role beyond publishing a blog. BuddyPress depends on WordPress.org, since it is a plugin for sites powered by that platform. It does not serve as separate software for a site on another platform. A site owner must use WordPress.org before adding BuddyPress and its profiles, activity streams, or user groups. This platform requirement may not fit people who do not run a WordPress.org site.