I took bdcravens' comment to mean it'd be a great project for someone who wanted a way to start contributing to OSS, not a suggestion that Facebook wasn't contributing.
Like whafro said, that wasn't what I was trying to suggest. Never meant to denigrate their contribution, only saying that parts that were never intended to be open (like comments) were probably removed rather than rewritten, which is perfectly acceptable and consistent with their great open source contributions.
