1. A computer-implemented method for development, delivery, deployment and operation of an application including executing instructions stored on a non-transitory computer-readable storage medium, the method comprising: receiving a request to launch an application within a platform associated with a namespace for the platform, wherein the platform is one platform of a plurality of platforms; responsive to receiving the request to launch the application, accessing a descriptor having an identifier that uniquely associates the descriptor with the application, wherein the descriptor comprises a single file that is platform independent and that includes a plurality of namespaces and application-specific attributes for each of the namespaces to enable the application to operate on multiple different platforms using a same descriptor, the single file of the descriptor comprising a single code portion and at least one configuration portion; selecting from the plurality of namespaces in the descriptor the namespace for the platform in which the application was launched; retrieving data by the application from the application-specific attributes from the selected namespace in the descriptor; accessing the single code portion of the descriptor by the application, wherein the single code portion comprises a read-only document and the single code portion contains application-specific code created prior to deployment of the application; accessing the at least one configuration portion of the descriptor by the application, wherein the at least one configuration portion references the single code portion and the at least one configuration portion comprises a write-enabled document containing customer-specific data; and configuring and operating the application using the retrieved data, the single code portion and the at least one configuration portion.