Apache Lenya - Looks like it could be good, but having tried the ‘incubating’ release it seems to be very slow and rather buggy. This could due to the demo site being unfinished, rather than the engine itself being poor.
Note added 21 Dec 04: Lenya is slowly moving out of incubating status, and looks like being a rather useful CMS - I should test it again soon.
Magnolia - Looks good, probably full featured, but has an enforced dual-server (admin and public Tomcats) system which is a bit annoying. I simply want to drop a CMS into a Tomcat running behind Apache via a mod_jk connector. Telling me I have to run two instances of Tomcat on 8081 and 8082 is not helpful, although presumably one can get around this. The Windows startup.bat doesn’t work either, and so presumably I have to find a free UNIX machine. I spent an hour faffing and could not get it started. It may require JBoss (it did say it was a J2EE thang), which would explain some of my trouble installing it.
Daisy Another CMS based on Cocoon. Looks quite good.