My only two contributions to Doug@50/#thedemoat50: glossary prototype (wait until it’s loaded: a completion message will appear after ~1-2 minutes, then click the light-blue italic words) and tracking changes on the character level while writing + visualizing them. Not too difficult to imagine both capabilities to be combined/integrated, what category of problems may arise and which sort of solutions would be required. More on the background of the glossary capability (there are also some blog posts: 1, 2 and 3) and the versioning capability. Try them yourself: glossary capability (might not work locally because of the stupid Same-Origin-Policy restriction in browsers) and change tracking text editor + history visualization (requires Java 1.6 or higher).
It’s pretty obvious that these are my personal results/solutions and not the result of a collaborative group effort. I just wasted a full year with trying to find a single individual in the contemporary hypertext community who would be interested in discussing, designing, building or using a capability infrastructure that powers a hypertext system architecture, likely because of incompatible differences in approach, paradigms, capacity, perspectives and goals.