METAKIT is a curious mix of flatfile, relational and OODBMS features with a
small footprint and a big following. For those who don't need a heavy-duty SQL
solution, it's tight and fast for <100,000 items, with a snazzy ability to
dynamically change data structures on the fly. Interfaces are available for
Tcl and Python, with Perl promised soon.

WWW: http://www.equi4.com/metakit/