We describe the work of the German Astrophysical Virtual Observatory (GAVO). GAVO is the German node in the world-wide international virtual observatory (VObs) effort aimed at making geographically distributed astrophysical data and applications more readily available to the community and to find ways of combining these in an interoperable network so as to create new ways of doing science. In this presentation we give a short overview of the ideas behind the virtual observatory and describe the efforts of the International Virtual Observatory Alliance (IVOA). We describe then in detail the activities of GAVO, both in its first pilot phase and in the recently initiated second phase. Here we will pay particular attention to the effort spearheaded by GAVO to include results of large scale computer simulations in the VObs efforts, both national and international
