That all makes sense. Thanks for layout out all the considerations.

If I understand correctly, there are multiple phases here.

I’m not sure any other library supports custom but restricted expressions for extended functionality. If it’s a concern, we could probably add a way to disable these custom expressions to restrict functionality but make the library safer for custom charts.

Good point on the docs/examples for timers. One example (albeit not a chart in the strict sense) is this clock: https://vega.github.io/vega/examples/clock/. There is also this rotating globe: https://vega.github.io/vega/examples/earthquakes-globe/.

Vega/Vega-Lite author here. Vega does actually support hyperlinks via the href property. See for example https://vega.github.io/vega/docs/marks/rect/. Vega also supports timers (https://vega.github.io/vega/docs/event-streams/) which can make animated visualizations. Happy to talk through any specific needs you have from Vega to make it useful for Wikipedia.

Note that Vega-Lite compiles to Vega and Vega-Lite isn’t needed anymore to run a chart. Since charts are viewed a lot more often than created, it would be good to cache the generated Vega and only load Vega for viewers.

Localization for Vega is described in https://vega.github.io/vega/docs/api/locale/. If you want to go back to formatting with numbers, you could also do that.

@Milimetric have you had a chance to look into this?

Thanks for the update. Let me know if there is anything I can help with.

As an author of Vega-Lite and contributor to Vega, I'd like to offer my support and help with this effort.