1. A system for processing a lightweight composite object that shares a parent with another lightweight composite object, comprising: a database for storing a lightweight composite object, one or more other lightweight composite objects, and a parent object instance, wherein the lightweight composite object and the one or more other lightweight composite objects share the parent object instance, wherein the lightweight composite object and the one or more other lightweight objects inherit data and behavior from the shared parent object instance, wherein the lightweight composite object and the one or more other lightweight composite objects each comprise a lightweight object instance and a link to the shared parent object instance, wherein the database stores one copy of the shared parent object instance; an interface for receiving an indication that a change is to be made to data associated with the lightweight composite object, wherein the data comprises data of the shared parent object instance; and a processor configured to: clone the parent object instance to create a new parent object instance; and designate the new parent object instance as the parent of the lightweight object instance corresponding to the lightweight composite object.