What JANA is:
JANA is a C++ reconstruction framework for developing reconstruction
code for nuclear physics experiments that use complicated
detectors and have high data volume.
What JANA is NOT:
JANA is not a final-stage analysis tool that one would use to
draw histograms or fit Ntuples/Trees/etc.. If you want that,
then take a look at
The JANA framework provides a modular way to build a complicated
reconstruction program. The framework incorporates mutli-threaded
event reconstruction in which each thread processes events
independently, allowing end users to maximize the processing rate
on multi-cpu and multi-core machines.
JANA also provides a well defined API for event "sources"
and "sinks" that, when coupled with it's ability to use
plug-ins makes it essentially capable of reading and writing
events in any format.