This software needs an installation of WordPress for it to get up and running. Of course, you can get one going if you use an automatic installer that supports it, but you can do just by going into your plugins section, going to Add New, and then searching for BuddyPress. If you want to get a new theme for your BuddyPress, all you have to do is go into the theme search and look up anything with BuddyPress in it.
This script is also rich in features! It has out-of-the-box social networking that includes activity streaming, forums, groups, PM (Private Messaging), and more! There are lots of users who can be more of a fan of the simpler stuff rather than facebook, and this is the crowd where facebook gets thrown out. If you want this script, don't try to run to0 big of a site, other wise you'll need your own server to keep running. Start off with shared hosting and move your way up! This is also a good way for friends that are especially into one topic to connect and share, without being put into a database of user surveilance!
The weakness of this si it's lack of features. If anything, it could give users a wall like facebook, or it could incorporate a user-friendly API creation so that users could connect their own user-programmed games. In fact, another weak spot is it's small problem with running larger sites. It needs some stronger code that can handle admin customization. If anything, it could probably run by itself, without a WordPress installation running its backend.
It is more user customizable than what you might expect. Just like WordPress, it's fanbase is growing because of the fact it's growing itself easier to use with less thinking. Administrators can customize who can join their community, and they can also delete spambots more easily by going into the WP backend. This makes the admins feel at home while users can customize what they use on the frontend. Also, it allows for easy user-grouping so that admins can easily track down who they want to see the info about. This is also a good way for users to keep in contact with their friends. Also, educational communities can easily block off education so teachers have control over who can be on and who can be off. It's a win-win situation.
I'm the admin of this site. WordPress does a good job on creating a social network out of itself, but let's not get stuck on using the same ideas over again! Instead of using WP for a backend, why not use a custom-built backend? Why not start over fresh? I know it makes the developers actually WORK, but at least it's worth a shot for getting a bigger fan base. Almost perfect!