It's far from complete, but a group of teammates from my University are developing Mumuki. The English version seems to be brokenEnglish version
seems to be broken doesn't have English content at the moment, but you can read it's intention there. You can also join the project and make it run C++ (I've started with C).
The idea of the platform is to create exercises with unit tests that check them.
We have started thinking about how to run the code in isolated ways, but up to now there's nothing implemented.