1. A method for storing and accessing data in a content management system, comprising: storing content data in content objects that include a plurality of property value bindings, the content objects being capable of binding properties to values, each property including a respective property type and the values being stored according to the property type corresponding to the respective property; generating and storing an object oriented content schema for modelling the content data by defining content object types, the content object types declaring required object properties wherein the content schema imposed constraint on the content objects, and the integrity of the content objects is examined by verifying constraints imposed on the content objects; accessing at least one of the content objects via the content schema; and recording one of resource version for modifications of the content objects and objects type definitions, wherein for the purpose of versioning, the content object and object type definitions are treated uniformly as resources.