The Official DESCENT 3 Web Site has the announcement of Descent 3: Mercenary, an official add-on for Descent 3, their recent sequel to the flying and shooting Descent series. Thanks Descent3D. The add-on will include some user-created levels, and there are details up on the contest that for third-party map authors to get their work included in the add-on if it's good enough. Not much more in the way of details about the new add-on are currently available.