Vanilla is a very flexible PHP+MySQL open source forum. It is characterized by various configurations, functions, and operation interface style that are very simple and elegant. In addition, Vanilla will list all posts directly on the homepage by default, in chronological order, and put the latest discussion posts at the front, similar to a blog. Vanilla is also highly extensible and its functionality can be extended through plug-ins.
Vanilla supports logging in using Twitter, Facebook, Google and other OpenID accounts.