Pushing the envelope of pervasive access

This paper presents the design and implementation of the Puma middleware system. Puma enables pervasive access to Web applications from a wide range of clients. In addition to traditional, browser-equipped client devices such as laptops and PDAs, Puma supports the use of peer collaboration tools such as instant messengers, SMS devices, email clients and telephones. While those collaboration tools were initially intended for free-form interaction between people, Puma leverages them for structured interaction between people and computers in order to offer more flexibility, convenience and intimacy to end users. In addition to user-initiated, or pull-based, interactions, Puma allows an application to proactively push an interaction to a user, in a manner sensitive to the application's needs and the user's current context. Architecturally, Puma employs various Modality Bots to mediate between application servers and heterogeneous clients. The Modality Bots also serve as the initial point of contact for application-initiated interactions. As an experiment, Puma has been used to mobilize the human tasks application, which supports the creation, processing, and management of the manual steps in business processes.