Unlike application programs that are shared over the network, copy of the operating system is installed on every computer. For this reason Fysikdatorn "backs up" only its own equipment (see hardware catalog for details) and prior right to use OS facilities is granted to all legitimate users of Fysikdatorn only on this equipment. On the other hand as vast majority of private UNIX-based workstations are Sun SPARC ones and payment conditions for corresponding software are well suited for bulk payment, Fysikdatorn finds it feasable to automatically bill units owning such equipment for SPARC Solaris Operating Environment (including development tools) in association with charging for own provided services (see price list for details) so that prior right to use SPARC Solaris facilities is granted to corresponding group members.