1. A computer system for designing internet-accessible datasets, the system comprising: a processor, computer-readable storage, and computer-executable instructions; the storage, in combination with the processor, providing a design space to a developer where the developer develops programs that call objects with methods and properties, each property comprising a lifetime statement, the lifetime statement specifying where the data of the property is to be stored and a lifetime comprising one of page, session, and application, and wherein the design space provides an event-driven model and input from the developer to the design space comprises events; the storage, in combination with the processor, further providing a composition space, the composition space being a serial execution environment; wherein the design space is configured to output documents containing the programs with the event-driven model and the input to the composition space; the system converting the programs from said design space into web pages for a runtime space in which said objects with the methods and the properties are represented as server-executable web pages and where a first page of said pages invokes a method or property from a second page of said pages wherein a design-time control of the first page locates and instantiates a design-time control of the second page for the invocation; and wherein when a method or property from the second page is invoked, the second page passes between the composition space and an interaction space across a server-client transition, wherein the runtime space becomes the interaction space when a remote client interacts with the server-executable web pages served by a server during the server-client transition, wherein in response to a request from a browser in the interaction space, the server-executable web pages execute and instantiate the objects with the stored property data persisted in the interaction space, wherein the browser receives the events and transmits the events and the stored property data to the composition space to handle the events.