The Moe Contest Environment (formerly MO-Eval) was a system for conducting programming competitions similar in spirit to the International Olympiad in Informatics – contestants solve programming tasks, submit the source code of their solutions, which is then automatically tested on a set of test inputs.
At this moment (2015-07-26), most parts of Moe are obsolete, but many of its ideas still live in other contest systems, most notably CMS.
The Isolate sandbox now lives in its own repository at GitHub.
Other useful parts will hopefully find their new home one day.
If you are still interested in what Moe once was, proceed to its old homepage.
You can download historical releases of Moe.