Cerealizer is a secure pickle-like module.

It support basic types (int, string, unicode, tuple, list, dict,
set...), old and new-style classes (you need to register the class
for security), object cycles, and it can be extended to support
C-defined type.

Cerealizer is available under the GNU GPL licence.

WWW: http://home.gna.org/oomadness/en/cerealizer/index.html