The core functionality that Facebook relies on exists in most open source web forums. A good developer could have easily built it on top of PHPBB back in the da

The core functionality that Facebook relies on exists in most open source web forums. A good developer could have easily built it on top of PHPBB back in the day - and probably had a more maintainable codebase. Yes - today's Facebook could not be built by a dev in a weekend, but Facebook 1.0? Not so hard.