Moodle
"Moodle is a software package for producing internet-based courses and web sites. It's an ongoing development project designed to support a social constructionist framework of education. Moodle is provided freely as Open Source software (under the GNU Public License)."--About Moodle
The XS School server includes a custom Moodle installation, tightly integrated with Browse.xo and other aspects of the XS. See the School server page for more details. More help is needed on polishing Moodle for young users, get in touch with our server-devel@list.laptops.org mailing list if you know Moodle code and can help.
The custom Moodle will soon provide a simpler UI, with a shorter list of modules and plugins, with as many things preconfigured as possible for ease of use. If there are Moodle Modules you'd like to see in our custom Moodle (official or from contrib), get in touch with our server-devel@list.laptops.org mailing list.
Martin Langhoff -- School Server Architect / Lead dev -- is a longtime Moodle developer. Moodletalk is always welcome on server-devel@list.laptops.org