Darcs compared to Arch
======================

Simpler to use; perhaps harder to completely understand.

Always local; always fast.

Patch commution is slow and perhaps doesn't clearly do what people
want.  

Too slow!

Can't reliably get back to any previous point.  Explicitly not
addressing source archive/librarian function.

Loads everything into memory.

Written in Haskell.

Breaking commits into hunks at commit time is interesting, but I think
not totally necessary.  Sometimes it won't break hunks where you want
it. 

A really simple pre-commit check hook is remarkably useful.

http://www.scannedinavian.org/DarcsWiki/DifferencesFromArch

Token replace
-------------

Very cute; possibly handy; not absolutely necessary in most places.
Somewhat limited by the requirement that it be reversible.

This is one of very few cases where it does seem necessary that we
store deltas, rather than tree states.  But that seems to cause other
problems in terms of being able to reliably sign revisions.

This can perhaps be inferred by a smart 3-way merge tool.  Certainly
you could have it do sub-line merges.