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.
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.