The PaCT-2009 (Parallel Computing Technologies) conference was a four-day eventheld in Novosibirsk. This was the tenth internationalconference to be held in the PaCT series. The conferences are held in Russia every odd year. The ?rst conference, PaCT 1991, was held in Novosibirsk (Academgorodok), September 7–11, 1991. The next PaCT conferences were held in Obninsk (near Moscow), August 30 to September 4, 1993; in St. Petersburg, September 12–15, 1995; in Yaroslavl, September 9–12, 1997; in Pushkin (near St. Petersburg), September 6–10, 1999; in Academgorodok (Novosibirsk), September 3–7, 2001; in Nizhni Novgorod, September 15–19, 2003; in Krasnoyarsk, September 5–9, 2005; in Pereslavl-Zalessky, September 3–7, 2007. Since 1995 all the PaCT Proceedings have been published by Springer in the LNCS series. PaCT-2009 was jointly organized by the Institute of Computational Mathematics and Mathematical Geophysics of the Russian Academy of Sciences (RAS) and the State University of Novosibirsk. The purpose of the conference was to bring together scientists working on theory, architecture, software, hardware and the solution of lar- scale problems in order to provide integrated discussions on parallel computing technologies. The conference attracted about 100 participants from around the world. Authors from 17 countries submitted 72 papers. Of those submitted, 34 were selected for the conference as regular papers; there were also 2 invited - pers. In addition there were a number of posters presented. All the papers were internationallyreviewedby at leastthree referees. A demo sessionwasorganized for the participants.