The CvsGui project is providing several high-end interface clients (WinCvs, MacCvs, gCvs) written in C++ using popular frameworks (MFC, PowerPlant, GTK+) with a scripting support via Python or TCL.
An attempt at a Xanalogical Web, comprised of a CGI system with both native and HTML interfaces, a set of standards, a backend supporting Transclusion, versioning, and a custom browser with support for Transpointing and editing.