Callisto CMS is an XML / XSL Web-based content management system built using Perl and AxKit. Includes WYSIWYG editor. This looks very promising. Matt Sergeant mentioned it a few months ago and I meant to discuss it in a follow-up to my XML & CMS essay, which I still plan to write someday. Callisto may help solve some of the problems I raise there.

I also want to keep an eye on Xopus, a browser-based WYSIWYG XML editor. At least one Good Thing has already come out of that project, and an open source release is scheduled for mid-summer.