Well, this is obviously our the first brick of our "Open Infrastracture". Among all free OS available today, we've choosen Linux, which finally is the title of this site. But wich distribution ? You don't have to know Linux very well to be informed that there are a lot of various distributions delivering a Linux OS. A distribution will deliver the Linux kernel and all that is needed to boot a server but also a lot of supplemental applications doing a lot of things like web servers, database servers, graphical desktops or office applications.