A reference architecture for the development of GLSP-based web modeling tools

Web-based modeling tools provide unprecedented opportunities for the realization of modern, powerful, and usable diagram editors running in the cloud. The development of such tools, however, still poses significant challenges for developers. The graphical language server platform (GLSP) aims to reduce some of these challenges by providing the necessary frameworks to efficiently create web modeling tools. However, realizing modeling tools with GLSP remains challenging and not much support for interested tool developers is provided yet. This paper discusses these challenges and lessons learned after working with GLSP and realizing several GLSP-based modeling tools. We present experiences, concepts, and a reusable reference architecture to develop and operate GLSP-based web modeling tools. As a proof of concept, we report on the realization of a GLSP-based UML editor called bigUML. Through bigUML, we show that our procedure and the reference architecture we developed resulted in a scalable and flexible GLSP-based web modeling tool for the UML. The lessons learned, the procedural approach, the reference architecture, and the critical reflection on the challenges and opportunities of using GLSP provide valuable insights to the community and shall ease the decision of whether or not to use GLSP for future tool development projects. With this paper, we publicly release a reference implementation of our architecture.