I just uploaded cells-ref.pdf and cells-ref.html (as generated by FrameMaker from the same .fm original) to the FTP site, in a new subdirectory dedicated to documentation:
ftp://common-lisp.net/pub/project/cells/doc
You'll see it is pretty much all over the map, and it needs an index and lots more examples, but I have been poking at it long enough and at this point would benefit from a round of requests for enhancment, so there it is. I'd rather be working on a port of Cello to an X environment, but will continue producing doc if anyone wants it.
Ongoing doc effort could be to refine these, or document the vital Family class, or document by example by producing fun sample code illustrating typical Cells code or... talk to me, I'm all ears.
kt