The littrack package is a part of CBMROOT framework. It provides track reconstruction in the transition radiation detector (TRD) and muon system (MUCH), track merging between STS, TRD and MUCH, TOF hit merging and finally it constructs global tracks based on this information.

For convenience and in order to decrease the dependencies between different parts of the littrack the package is divided into four main parts:

Interface to CBMROOT of littrack - everything that is related to interface of the tracking software to CBMROOT, quality checks etc.
Standard tracking implementation - "standard" scalar implementation of the tracking using full magnetic field map and TGeo for geometry navigation. It depends on ROOT and does not depend on CBMROOT.
Parallel implementation in littrack - SIMDized and multithreaded implementation of the tracking. It depends only on the compiler and can be used in standalone mode for performance testing.
CUDA implementation in littrack - currently not so much progress in this direction...only few test implementations...

littrack also provides a list of ROOT-macros to run the track reconstruction and perform quality checks.