This document describes YaKa, a complete solution for deploying operating systems on large computer site. Unlike most existing tools Yaka is based on a compiled approach. It provides a language allowing to describe a computer site as a whole and at all levels: host hardware, systems to install on the hosts, links between host systems, software generation. Using this description a compiler generates automatically the systems to be installed for each host and generates the network installation servers. All generated systems are ready to use and fully operational on their first run. All systems are generated in a single operation so every component is generated with a complete knowledge of all the other components of the system and a complete knowledge of the network relationship between the hosts. This ensures the coherence of each piece of software with the other softwares of the system and with the environment of the host. By reducing the amount of components needing to be installed and the complexity of the startup scripts, this drastically decreases the duration of system installation and the duration of the boot. This allows to do statically a lot of verifications. This allows to group tools together to provide abstract services. The power of the language is also demonstrated by describing a complete source based Linux distribution. The efficiency and reliability have been demonstrated by its use for several years to manage the teaching network our postgraduate school.(10 servers, 100 clients with heterogeneous hardware, different operating systems and software).