The topmost meeting of experts in the area of nuclear physics and elementary particle physics, took place in Prague March 21-27, 2009. It provided an international science forum for exchanging information on computing experience and needs for the High Energy and Nuclear Physics communities, and also reviewed recent, ongoing and future activities. CHEP conferences are held in 18-month intervals (the last conference was held in Canada 2007). Nuclear physics and elementary particle physics (called high-energy physics today) represent branches that are also crucial for development in the area of computers and data processing. For example, it is particle physics that is credited for the emergence of the World Wide Web. and Alan Silverman, Miloš Lokajíček a Jiří Rameš, Jiří Dolejší.