For last two years many MOOC aggregators appeared. All of them are just flat list of courses. Only some of them allow filtering and search.
We also have the list of MOOCs and online courses (which is biggest, by the way). However, we decided to create something new. Some new interface to search courses more intuitively.
This is why we created MOOC Calendar. On our opinion, calendar view is best for such cases. More then half of online courses, especially MOOCs, have start date defined. alendar view is the best for such courses finding.