Monolith's Jason Hall updated his .plan with a "translation" into layman's terms of the press release about the availability of their LithTech 2 engine on the Playstation 2 (story). Here is an excerpt from the full explanation:

Something to know - there may be other engines out there that are currently being ported to the PSX2, but until they are approved, they are not able to be made available for others to license. This is why this announcement is significant. As far as I can tell, LithTech is really the one and only complete 3D game operating system available to license as a middleware solution.