Xivio.com was a commercial children's virtual world website created in 2006 by Gavin Conrad. This is the legacy World Server Java Core made available to the world to do with as it wishes.
An alternative/custom Minecraft server, written in Java, compatible with the original protocol. OpenCraft is built upon Apache MINA, SLF4J, Jython and XStream. The aim is to have features not in the official server distribution, like antigrief/scripting.
MobileStratego is the online version of Stratego for mobile phones. It's developed with J2ME and it is a two players version. Online playing is achieved using peer-to-peer with virtual server or direct connection. Single phone is supported too