The offline systems currently developed by LHC experiments will soon
reach sizes of multi million lines of code written by teams distributed
all around the world. These systems will be operational for at least two
decades and will be in constant evolution to reflect changes in the
algorithms, languages, computing infrastructure and detector. A
substantial fraction of this software is expected to be experiment
independent. We are only four years away from the first LHC events. The
deployment of the experiment specific software requires a stable and
proven software framework with an agreed development path. The choice of
the framework will have a direct impact on the end user.
The ROOT project is an attempt to provide a common and coherent framework
for developing experiment-dependent software. ROOT has been developed in
close collaboration with many experiments and is becoming the de facto
standard for object storage and interactive data analysis in High Energy
and Nuclear Physics experiments. The seminar will illustrate several
important aspects of the ROOT framework (Object dictionary, Object
persistency, C++ interpreter, Plug-in manager, etc) with emphasis on the
hierarchy and relationship between the sub components. The planned
development strategy will be presented.
