Web-based EEG/MEG browser/viewer

I've recently been pointed to #12030, where a web-based viewer for 3D brain images is suggested (great idea BTW). In related news, Anaconda is currently working on implementing a web-based time series browser/viewer specifically for EEG/MEG signals (using HoloViz and Bokeh). I've been in contact with @droumis from the beginning of the project to make sure that it could be a viable alternative backend for our raw browser.

If you are interested, this is their main project website: https://github.com/holoviz-topics/neuro

The relevant workflow for us is Stacked Timeseries: https://github.com/holoviz-topics/neuro/blob/main/workflows/stacked-timeseries/0-StackedTimeseries.ipynb

The project will be running for 12 more months, so if you have specific feedback and/or feature requests, please feel free to drop them here. Demetris said that they are currently focussing on performance with large datasets. The viewer already includes an overview bar, and they included independent subcoordinate y-axis scaling and a dynamic scale bar. Here's a short demo video showing off annotations, hover tooltips, and minimap navigation: https://github.com/holoviz-topics/neuro/pull/82

And of course, you can always try out the workflow by installing the conda env described in the main README.

Start with the referenced #12030 issue and the external Stacked Timeseries workflow in holoviz-topics/neuro, then compare it with MNE's existing raw browser entry points. The issue asks for feedback or feature requests rather than defining a concrete MNE change, so completion criteria and implementation scope would need to be established first.