Mantissa is an application server built on Twisted and Axiom. It provides mechanisms for allowing users to sign up for accounts, administrative tools, a web server, and a system for different plugins which provide facets of functionality to advertise themselves to the administrator, install themselves on the site database, and be installed and removed from users' accounts. Mantissa has significant web-based functionality (mostly built on Nevow/Athena) but is protocol-agnostic.

NOTE: Development of this project is conducted in the divmod.org project branches; if you are looking for source code, see https://launchpad.net/divmod.org for more.