What do you mean by "manipulating an arch repository"?
For example, for CVS I can interact with a CVS repo with any of the following tools:
- WinCVS (CVS Gui for windows)
- TortoiseCVS (Windows Explorer shell extension)
- pcl-cvs in Emacs
- CVS plugin for Eclipse
- ViewCVS web interface
Just to name a few. That way my less command-line savvy users have the warm fuzzies of a GUI. And WinCVS in particular has a really cool graphical branch viewer that makes it easy to see what happened in the past. Those kinds of things. "Third Party Tool Support" for lack of a better term is what I was thinking.
Emacs integration in particular is something we would really miss.