The Daily Grind: Open source MMOs

In an amazing bit of news yesterday, Cyan Worlds decided to fully open-source Myst Online: URU Live. When we say fully, we mean it - art, client code, server code, development engine, everything. It was a bold move for Cyan to take; essentially trusting in the fans and other MMO addicts to take their code and continue growing Myst Online: URU Live.
This morning we thought we'd ask - now that this first step has been taken, what other games would you like to see go open source? Which ones would you like to work on, purely as a fan contribution? What would you build into those worlds if you were given the chance?
This article was originally published on Massively.