Introducing BIGUML: A Flexible Open-Source GLSP-Based Web Modeling Tool for UML

Unified Modeling Language (UML) plays a crucial role in software development by providing a standardized notation for visualizing, specifying, and documenting system architectures. Traditional UML modeling tools often follow a rich client approach and suffer from limitations such as steep learning curves and restricted extensibility. Usually, those tools are also proprietary and constrained to specific platforms. This paper presents BIGUML, a flexible, open-source UML modeling tool implemented as a Visual Studio Code extension leveraging the Graphical Language Server Protocol (GLSP) to offer a seamless modeling experience with rich features and enhanced usability. The early release already supports the Class and the Use Case diagram, further UML diagrams will follow soon iteratively. We introduce BIGUML and highlight, how its flexible architecture allowed the integration of custom features, such as the property and outline view, and contextual copy-paste operations. The BIGUML modeling tool is one of the first tools to incorporate GLSP and to be distributed through the VS Code ecosystem.