Minor gripe: Make individual apps their own repositories so other people can include them in other projects.

If you want to update mochiweb, itap, etc on couchdb and bigcouch, do you manually patch the changes into every repository? Is erlang-oauth in couchdb the same as oauth in bigcouch?

Look at riak for the Right Way™ to package Erlang apps: The main riak repository has no erlang code (http://hg.basho.com/riak/src/tip/rebar.config). It has one dependency of riak_kv which in turn includes everything else needed (http://hg.basho.com/riak_kv/src/tip/rebar.config).

Learn to love the gift of rebar -- recursive dependency resolving.