"Matthew O. Persico" <mpersico(a)erols.com&gt; writes: I think it can be done unless the model is complete different from CVS/RCS/SCC. Just look for the symbol 'CVS in vc.el to see where to hook in. However please mark all changes relative to the FSF version (and resist the temptation to change the inner workings of vc.el too much) this will allow syncing with FSF. I took care of marking all our diffs with the FSF 20.2 version with ;;XEmacs If the VC system is free in the FSF sense it is best if the changes could be submitted to the FSF version maintianer for inclusion. Jan Vroonhof Inofficial Feeling-responsible-for-XEmacs-vc.el-person