TWiki a collaboration tool for the LHC

At the European Laboratory for High Energy Physics, CERN[1], the Large Hadron Collider (LHC)[2] accelerator is colliding beams of protons at energies of 3.5 TeV, recreating conditions close to those at the origin of the Universe. The four main LHC experiments, Alice, Atlas, CMS and LHCb are complex detectors with millions of output channels. These experiment detectors, "large as cathedrals", have been designed, built and are now operated by collaborations of physicists from universities and research institutes spread across the world. Wikis are a perfect match to the collaborative nature of CERN experiments and since TWiki[3] was installed at CERN in 2003 it has grown in popularity and the statistics from April 2011 show nearly 10000 registered editors and about 110000 topics (Figure 1). Since the start-up of the LHC more and more users are accessing TWiki requiring better server performance as well as finer control for read and write access and more features. This paper discusses the evolution of the use of TWiki at CERN.