The folks at SUNY Learning Network have proposed the concept of a "Learning Management Operating System". One of the proponents is Michael Feldstein, who happens to be a good friend. I understand the motivation for LMOS --- the perennial itch for modularity and interoperability -- but haven't yet been able to put my arms around the concept. Also, isn't this what Sakai is supposed to be all about? Stephen Downes has weighed in and thinks that an LMOS is hopelessly over-engineered.