Fedora is the underlying operating system on the OLPC XO laptop. This is the Linux distribution (previously called "Fedora Core") developed by Fedora Project and sponsored by Red Hat.
Because it is the Linux base chosen by the OLPC on which to develop Sugar, it is a reference for any other Linux distribution attempting to run on the XO-1 hardware or present the Sugar UI on a conventional computer.
Each OLPC software release has been based on a version of Fedora, for example 10.1.3 is based on Fedora 11. Over time, the OLPC operating system has moved closer to a "stock" Fedora release with some additional olpc packages, created with the OS Builder tool.
Fedora Core 6 uses the SCIM (Smart Common Input Framework) system to support multiple IMEs and keyboard layouts for multiple writing systems and languages. This includes Chinese, Japanese, Korean, and many other languages.
If you have a Fedora distribution running on a computer, you can install the Sugar environment that runs on the XO laptop.