On the php|architect site today there's a wrap-up from Keith Casey about the latest DC PHP User Group meeting where Scott MacVicar from Facebook presented on HipHop.

[Scott's] title is "Open Source Developer Advocate" which puts him in the odd position of making good things happen within Facebook, representing them to the community, and convincing the community to get involved. Towards that goal, this presentation was the last stop of a short tour to present HipHop to PHP groups.

He mentions the stats Scott shared - the size of Facebook's image hosting, the time spent on the site by the average user - and, of course, details on how HipHop helps them with his crushing load of users. He was also asked a question on the lips of many a developer out there - why would Facebook release HipHop for public consumption? You'll have to read the post to find out.