"The Connexions Project":http://cnx.rice.edu currently hosts 1480 interlinking modules of academic content under a "Creative Commons":http://creativecommons.org license, some of which form 21 full university courses created at five universities worldwide. Among the courses available are music theory, steel design, gene finding, bioinformatics, computer logic, image coding, and digital signal processing.
The move to Plone from the previous Zope site started half a year ago and involved Connexions staff and "consultants":http://jcameroncooper.com. The effort produced several major features for Plone such as "groups integration":http://ingeniweb.sourceforge.net/Products/GroupUserFolder/ and the "PasswordResetTool":http://sourceforge.net/projects/collective, as well as Zope Products like "ExtZSQL":http://zope.org/Members/jccooper/extzsql.
The migration will be the subject of a talk at the upcoming Plone conference in New Orleans.