CERN (European Organization for Nuclear Research) is one of the world’s largest and most exciting centres for fundamental physics research. CERN is also famous for being the place where Tim Berners-Lee  invented the World Wide Web. Most of the activities at CERN are currently directed towards operating the world’s biggest elementary particle accelerator - the Large Hadron Collider (LHC), and running the four largest experiments at the LHC (ALICE, ATLAS, CMS, LHCb). These seek to expand the frontiers of knowledge and complete our understanding of the constituents of matter and their interactions, of the conditions in the first instants after the Big Bang and of the differences between matter and anti-matter.

Fear not! The vast majority of our GSoC projects do not require any physics knowledge.

The CERN Virtual Machine (CernVM) is an R&D project established in the Software group of CERN’s Physics Department (PH/SFT) to investigate how virtualization technologies can be used to improve and simplify the daily interaction of physicists with experiment software frameworks and the Grid infrastructure. CernVM maintains a Virtual Software Appliance designed to provide a complete and portable environment for developing and running LHC data analysis applications on any end user computer (laptop, desktop) as well as on the Grid and on Clouds.

Geant4 is a toolkit for the simulation of the interactions of radiation with material.  It is used to simulate interactions in the detectors of the LHC and other High Energy Physics (HEP) experiments and in diverse other fields. Examples outside HEP include using it to assess the effects of radiation on the electronics of satellites and to design improved medical detectors with specially designed applications such as GATE. LHC experiments use Geant4 to compare the signatures of events from new physics (such as the Higgs boson and particles which are candidates for dark matter) to the signatures of events coming from known interactions which could mimic them. Geant4 is created by the Geant4 collaboration of 90 physicists and engineers from around the world, spaning teams at leading High Energy Physics laboratories such as CERN (Geneva, Switzerland), Fermilab (Batavia, IL), KEK (Tsukuba, Japan), SLAC (Stanford, CA) and Triumf (Vancouver, Canada), as well as many universities and institutions. The toolkit continues to be developed to improve its precision and scope of application, and to better utilise current and emerging computer architectures.

The ROOT system provides a set of OO frameworks with all the functionality needed to handle and analyze large amounts of data in a very efficient way. Having the data defined as a set of objects, specialized storage methods are used to get direct access to the separate attributes of the selected objects, without having to touch the bulk of the data. Included are histograming methods in an arbitrary number of dimensions, curve fitting, function evaluation, minimization, graphics and visualization classes to allow the easy setup of an analysis system that can query and process the data interactively or in batch mode, as well as a general parallel processing framework, PROOF, that can considerably speed up an analysis.