Congrats to the folks over at Technology Resource Foundation  for actually delivering a Technical Beta Preview of OpenBook  roughly upon their promised date. It looks to be an already working system, guaranteed to wow (if the OSSIG session at ALA last month is an accurate gauge), if still at the to-be-expected not-fully-polished state of an 0.8 release.
OpenBook is a Koha -inspired, GPL-licensed system, apparently rewritten from scratch in more than 20k lines of php. [Update 2001-7-16: see this post on the Koha list  for TRF's announcement and more explanation of the relationship between OpenBook and Koha. -dc]