We just published a first release of JupyterCAD, a demonstrator of a web 3-D parametric modeler built upon JupyterLab and Open Cascade, with collaborative editing features (à la Google Docs). You can find our blog post on this here. This is all open-source.
I think this demonstrates the potential of the JupyterLab foundations to build complex frontend applications in the web (with a flexible plugin system, configuration system, unified internationalization, themes, visual regression testing, real-time collaboration).
Should there be an interest in developing a Web front-end to Salome and parts of the Salome ecosystem, we would love to be in touch with the relevant people. Our team comprises the main contributors to the Jupyter project with a strong track record of building scientific computing open-source software.
Looking forward to your feedback.
CEO @ QuantStack
Software Steering Council @ Project Jupyter
General Chair @ JupyterCon
Director @ NumFOCUS