I had a request to make a very quick summary of the PHPSpec API for the current development snapshots over on http://dev.phpspec.org. We're lacking documentation for right now, so here's a brief overview.

He describes some base assumptions about the development so far, conventions for making a valid spec class (including "fleshed out code" to make it work), a list of the Matchers currently available and a mention of the Predicates to help with the evaluations.

You can also check out some of his thoughts on the project and behavior-driven development as it hit its 100th Subversion revision.