Does anyone know of K-12 textbook publishers (or other content creators) that also sell IMS Common Cartridges or other course content that can be imported in Moodle? I'm hitting a lot of dead ends in my attempts to find anything out there...
I too have found few. However, there is another movement in development: LTI - Learning Tools Integration.
Please see: http://www.imsglobal.org/toolsinteroperability2.cfm
and Moodle is listed as one of the members - or something like that.
There are some big players in there including publishers like Pearson.
LTI is present in version 2.2 of Moodle and an add on for the flip side - LTI provider (still in the works of perfecting).
While IMS CC is one way, LTI also provides some interesting possibilities for 'sharing' collaboratively developed content among Moodles.
'spirit of sharing', Ken