Participants of the XXV IUPAP Conference on Computational physics came to Moscow at the end of the August during a hot period. It was not a hot period because of the summer; in fact, the weather was quite comfortable. It was a hot period for the atmosphere amidst scientific society in Russia, especially for scientists working for the Russian Academy of Sciences.Four years ago, the C20 IUPAP Commission on Computational Physics and Computational Physics Group of the European Physical Society chose Moscow for several reasons. The first reason was connected to the high level and deep traditions of computational physics in Russia. It is known from experience at the former CCP conferences that native participants contribute about half of the presentations which form the solid scientific background of the conference, and the good level of domestic science makes the conference interesting and successful. The second reason was due to the fact that for the last twenty years there were not many IUPAP conferences in Russia, and it was a time to open more places for information exchange and intensify scientific collaboration. Thirdly, it was common opinion four years ago that the situation in Russia had become stable enough after the transition to a modern society, which took almost a quarter of a century. The conference preface is continued in the pdf.