With lots of help from Tobias on #lisp, I've discovered an issue with slime-forward-cruft. I think xemacs doesn't understand "[:space:]" in skip-chars-forward. Changing that to "[\\s]" makes arglists work. The issue shows up when trying to get autodoc[1] to show the arglist for "(cos". This failed because it was looking for "os". The above fix makes it work again. Thanks to Tobias for helping me find this. Ray [1] Yes, I know slime-autodoc is disabled for xemacs, but I have a verbatim copy of eldoc from emacs that runs just fine on xemacs, so I hacked slime-autodoc not to error out when loaded for xemacs.