The ZODB is an object database that allows for comparably natural storage of Python objects. Its top features are transparent persistence for Python objects, full ACID-compatible transaction support (including savepoints), a history/undo ability, efficient support for binary large objects (BLOBs), pluggable storage, and a scalable architecture. The database has a proven track record for about ten years in large applications.
GroupServer is a Web-based mailing list manager designed for large sites. It provides email interaction like a traditional mailing list manager but also supports reading, searching, and posting of messages and files via the Web. Users have forum-style profiles, and can manage their email addresses and other settings using the same Web interface. It has supports features such as Atom feeds, a basic CMS, statistics, multiple verified addresses per user, and bounce detection, and is able to be heavily customized.