This is a work in progress of a very stable version by Laurens Valk.
Based on his earlier work, the anyway and the segway for Aplha-Rex2.
See also more information here and here.
The education version made by Lee and with software from Danielle.
The building instructions are available here, but the code is still part of the paid EV3 education version, and I can not just disclose it , (unfortunately).
More information about the education software here
And this is a special Java version, with tux as their model, more information here.