Magic Cap (short for Magic Communicating Applications Platform) is a discontinued object-oriented operating system for PDAs developed by General Magic. Tony Fadell was in charge of the platform. Darin Adler was an architect.
Magic Cap incorporated a "room metaphor", where the user navigated from room to room to perform various tasks (e.g. a home office to perform word processing, or a file room to clean up the system files). The interface resembled that of Microsoft Bob, though Magic Cap lacked an office assistant.
Several electronic companies came to market with Magic Cap devices, the most notable of which being the Sony Magic Link released in 1994 and the Motorola Envoy, also released in 1994. None of these devices were commercial successes.
Magic Cap Wikipedia
The Magic Cap operating system included a new "mobile agent" technology named Telescript. Conceptually, the agents would carry work orders, travel to a "Place" outside of the handheld device, complete their work, and then return to the device with the results. When the Magic Cap devices were delivered, the only Place for agents to travel was the PersonaLink service provided by AT&T. The agents had little access to functionality, since each agent had to be strictly authorized and its scope of inquiry was limited to the software modules installed on the PersonaLink servers. The payload carried by these agents was also hampered by the slow baud rate of the modems in the devices of 2400 bit/s.
The authentication/authorization system of the mobile agents in Telescript created a high coupling between the device and the target Place. As a result, deployment of agent-based technology was incredibly difficult, and never reached fruition before the PersonaLink service was shut down.