DEPRECATED - FOR APOSTROPHE 0.5 SITES ONLY - BUILT IN TO APOSTROPHE 2.X. Allows any object to have a schema of properties that can be edited in the browser, sanitized on the server and easily saved in Mongo. Schema types include text, select, tags, Apostrophe areas and singletons, and joins (one-to-one and many-to-many relationships), among others.