The OLPC XS (often spoken as "School Server") is a Linux-based OS (a Fedora-based distribution) designed to be installed on generic low-to-midrange mildly ruggedized servers. Initial plans of building a custom server geared for the role have been postponed, OLPC however offers hardware recommendations for the system, and plans to support the XO laptops running as a server for very small schools.
OLPC XS can provide children's XO laptops and their Sugar Learning Platform with network connectivity for backups, anti-theft leases, web browsing, system, content updates, asynchronous collaboration tools such as Moodle, etc.
Read more about OLPC XS: Projected Specifications