Content/Learning Management Systems

Wikpedia definition for CMS
http://en.wikipedia.org/wiki/Content_Management_System

Wikipedia definitonn for LMS
http://en.wikipedia.org/wiki/Learning_management_system

Moodle - open source LS
http://moodle.org/
http://moodle.com/

OTAN Moodle
http://moodle.otan.us/

Blackboard
http://www.blackboard.com/

Hot Chalk
http://www.hotchalk.com/index_new.html

A collection of bookmarks about LMS
http://www.delicious.com/branka_m/lms