"Notoriously, S5 does not work with real XHTML, because the Javascript was not created in an XHTML-safe fashion. This has been fixed in my distribution."
"Thanks to Ryan King, we now have S5 Project, which will be the official home of S5. Besides the blog and mailing list S5-discuss, there will be a wiki, a source code repository, and a bug-and-feature-request tracking system."