  In the past decade, the modeling community has produced many feature-rich
modeling editors and tool prototypes not only for modeling standards but
particularly also for many domain-specific languages. More recently, however,
web-based modeling tools have started to become increasingly popular for
visualizing and editing models adhering to such languages in the industry. This
new generation of modeling tools is built with web technologies and offers much
more flexibility when it comes to their user experience, accessibility, reuse,
and deployment options. One of the technologies behind this new generation of
tools is the Graphical Language Server Platform (GLSP), an open-source
client-server framework hosted under the Eclipse foundation, which allows tool
providers to build modern diagram editors for modeling tools that run in the
browser or can be easily integrated into IDEs such as Eclipse, VS Code, or
Eclipse Theia. In this paper, we describe our vision of more flexible modeling
tools which is based on our experiences from developing several GLSP-based
modeling tools. With that, we aim at sparking a new line of research and
innovation in the modeling community for modeling tool development practices
and to explore opportunities, advantages, or limitations of web-based modeling
tools, as well as bridge the gap between scientific tool prototypes and
industrial tools being used in practice.
