...Provides an easy way to persist objects using persistent collections. The basic idea is provide a way to write programs that use persistent data without break OO concept like RDBMS and without complexity of an OODBMS.
Metakit is an efficient database library with a small footprint. It's a cross between flat-file, RDBMS, and OODBMS.
Keywords: structured storage, transacted, load on-demand, portable, C++, Python, Tcl, instant schema versioning.