crunchyfrog : Cross-plattform SQL client for a variety of DBMS. ( http://crunchyfrog.googlecode.com/ )
hamsterdb : A lightweight embedded database engine. ( http://hamsterdb.com/ )
pgcli : Postgres CLI with autocompletion and syntax highlighting ( http://pgcli.com/ https://pypi.python.org/pypi/pgcli )
redis : A persistent caching system, key-value and data structures database ( http://redis.io/ )
tdb : TDB is a Trivial Database (mainly used by Samba) ( http://www.samba.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a dev-zero
For Paludis use this rsync : rsync://gentoo.zugaina.org/dev-zero-portage
If you have a problem : ycarus(-at-)zugaina.org