distributed

This paper describes Visual Obliq, a user interface development environment for constructing distributed, multi-user applications. Applications are created by designing the interface with a GUI-builder and embedding callback code in an interpreted language, in much the same way as one would build a traditional (non-distributed, single-user) application with a modern user interface development environment. The resulting application can be run from within the GUI-builder for rapid turnaround or as a stand-alone executable. The Visual Obliq runtime provides abstractions and support for issues specific to distributed computing, such as replication, sharing, communication, and session management. We believe that the abstractions provided, the simplicity of the programming model, the rapid turnaround time, and the applicability to heterogeneous environments, make Visual Obliq a viable tool for authoring distributed applications and groupware.

Distributed client/server models are becoming increasingly prevalent in multimedia systems and advanced user interface design. A multimedia application, for example, may play and record audio, use speech recognition input, and use a window system for graphical I/O. The software architecture of such a system can be simplified if the application communicates to multiple servers (e.g., audio servers, recognition servers) that each manage different types of input and output. This paper describes tools for rapidly prototyping distributed asynchronous servers and applications, with an emphasis on supporting highly interactive user interfaces, temporal media, and multi-modal I/O.

The Socket Manager handles low-level connection management and device I/O by supporting a callback mechanism for connection initiation, shutdown, and for reading incoming data. The Byte Stream Manager consists of an RPC compiler and run-time library that supports synchronous and asynchronous calls, with both a programmatic interface and a telnet interface that allows the server to act as a command interpreter. This paper details the tools developed for building asynchronous servers, several audio and speech servers built using these tools, and applications that exploit the features provided by the servers.

This research explores distributed sensing techniques for mobile devices using synchronous gestures. These are patterns of activity, contributed by multiple users (or one user with multiple devices), which take on a new meaning when they occur together in time, or in a specific sequence in time. To explore this new area of inquiry, this work uses tablet computers augmented with touch sensors and two-axis linear accelerometers (tilt sensors). The devices are connected via an 802.11 wireless network and synchronize their time-stamped sensor data. This paper describes a few practical examples of interaction techniques using synchronous gestures such as dynamically tiling together displays by physically bumping them together, discusses implementation issues, and speculates on further possibilities for synchronous gestures.

This paper describes a new technique for transferring data between computers, the synchronized clipboard. Multiple computers can share a synchronized clipboard for all clipboard operations, so that data copied to the clipboard from one computer, using the standard Copy command, can be pasted directly on another computer using the standard Paste command. Synchronized clipboards are well-suited for a single user moving data among several computers in close proximity. We describe an implementation of synchronized clipboards that works across a wide range of existing systems, including 3Com PalmPilots, Microsoft Windows PCs, Unix workstations, and other Java-capable platforms. Our implementation adds no noticeable overhead to local copy and paste operations.