TUDOS sources are available as snapshot releases and via SVN. If you just want to play around, you can download the Live CD.
The software consists of multiple components:
- The kernel Fiasco.OC
- The L4Re runtime environment running on top of Fiasco.OC
- An optional paravirtualized Linux: L4Linux
The runtime environment L4Re itself consists of many packages that implement various functionality and depend on each other. The check-out mechanism makes sure that all required packages are downloaded.