Vasum is a Linux daemon and a set of utilities used for managing para-virtualization. It uses Linux Containers to create separate, graphical environments called the zones. One can concurrently run several zones on one physical device. Vasum exports a rich C/DBus API that the application frameworks can use to interact with zones.
For now Vasum uses LXC for Linux Containers management. The project is mostly written in modern C++ and is well tested.
Vasum's development takes place on review.tizen.org/gerrit/ (registration on tizen.org is required).
Fedora 22 Desktop running in Linux container on youtube
The installation process and simple verification is described here.
Vasum daemon can be accessed via C API or DBus. You can find the API documentation here. Be aware that the API will most likely change in the near future.