Helveg: Diagrams for Software Documentation.

Software developers often have to gain an understanding of a codebase. Be it programmers getting onboarded onto a team project or, for example, developers striving to grasp an external open-source library. In either case, they frequently turn to the project's documentation. However, documentation in its traditional textual form is ill-suited for this kind of highlevel exploratory analysis, since it is immutable from the readers' perspective and thus forces them to follow a predefined path. We have designed an approach bringing aspects of software architecture visualization to API reference documentation. It utilizes a highly interactive node-link diagram with expressive node glyphs and flexible filtering capabilities, providing a high-level overview of the codebase as well as details on demand. To test our design, we have implemented a prototype named Helveg, capable of automatically generating diagrams of C# codebases. User testing of Helveg confirmed its potential, but it also revealed problems with the readability, intuitiveness, and user experience of our tool. Therefore, in this paper, which is an extended version of our VISSOFT paper with DOI 10.1109/VISSOFT64034.2024.00012, we address many of these problems through major changes to the glyph design, means of interaction, and user interface of the tool. To assess the improvements, this new version of Helveg was evaluated again with the same group of participants as the previous version.