Please wait a few days more, then CLPython will have a few sepate ASDF systems, and will be restructured into different packages and directories. There is still reliance on Allegro CL (not Lispworks), though.
Sorry, holes in memory.
Portability is not easy. Like, there is no portable way to use environments and custom declarations, while much compiler logic is currently based on that. Maybe other CL implementations offer functionality similar to Allegro; in that case there's hope to get it running on those implementations too. (Or someone could try to restructure the compiler; that probably won't be me as I'm happy with the current setup.)
Kind of narrows the posiblities, as i am only familiar with non compiler specific common-lisp, and to make such a restructuring one would have to know ACL pretty well.
Supporting other implementations is a wish, but not the main goal for me personally, so please join development if you want to realize it.
Some time ago you have mentioned the lack of contributors, and i think that depending on a commercial common-lisp implementation is one of the main factors limmiting the amount of developers who can work on the project. But I guess you have no more free time to port CLPython as I do, maybe even less.
Ignas