Project Peanut

A total conversion with a bunch of gameplay enhancements like new godly magic, shops, new monsters, new items, new classes and all-new maps.

http://peanut.ravencommunity.net (*)

RavenHurst

This is a single player mission pack being worked on by Razumen.

http://www.raven-games.com/hosted/ravenhurst

Agent Chaos

A project that has unfortunately never been finished. It'd have featured several hubs, a full new background story and a lot of new models. Though you'll most probably never be able to play it, there is still good stuff in abundance like concept art, model screenshots and an extensive background story.

http://www.planetheretic.com/agentoc

*: This site/page is not avaiable