Sirius Web is an open-source, web-based language workbench maintained by Obeo and hosted under the Eclipse Foundation. It is the successor of Sirius Desktop, an Eclipse-based language workbench used for producing numerous industrial graphical modeling workbenches in the past decades. Leveraging on this valuable experience, in this article we provide an overview of Sirius Web and document the rationales and good practices that have shaped its development. Specifically, we focus on: 1/ the rationales behind modeling and usability features; 2/ their impact on the development lifecycle of tool-supported modeling languages; 3/ the software architecture of the language workbench and the resulting modeling environments. Concrete examples illustrate both the detailed rationales and the use of the tool. We also discuss alternative approaches Obeo considered. In addition to introducing Sirius Web, this paper also aims to help language workbench developers make informed design choices for the future development of web-based language workbenches. It also identifies current open questions for the software language engineering community. Moreover, by addressing current open questions in software language engineering, this study contributes to the ongoing dialogue in the community, potentially steering future research directions.