We describe a package of practical tools and libraries for manipulating graphs and their drawings. Our design, which aimed at facilitating the combination of the package components with other tools, includes stream and event interfaces for graph operations, high-quality static and dynamic layout algorithms, and the ability to handle sizable graphs. We conclude with a description of the applications of this package to a variety of software engineering tools.

The typical computer application follows a set pattern: it is executed by a user, it provides responses to commands issued by the user, and it is terminated by the user when it is no longer needed. However, the advent of networked computers and the World-Wide Web has changed the way many applications work. Agents and similar programs constantly access online information databases and identify items that may be of interest to their users. The problem lies in communicating the collected information. Most existing widgets cannot take full advantage of the constant information flux generated by these programs. They work best as part of a full-screen display, they do not react well to changes in information, or they cannot attract the attention of users when new information arrives. This paper explores these problems and describes anumber of interactors that may help alleviate them.