MapLibre GL is a community-led open-source fork derived from Mapbox GL JS prior to their switch to a non-open-source license. It is tagged as the official successor to Mapbox GL JS.
This past December Mapbox announced that starting Mapbox GL JS version 2.0 would be released under a proprietary license. Older versions will continue to be available as open-source though going forward, Mapbox will only be investing in developing new features for the proprietary version.
MapLibre GL is considered the official open-source successor to Mapbox GL JS. This is as a result of the effort to avoid fragmentation with this library due to the sheer number of forks that were created following Mapbox’s announcement.
For those that depend on mapbox-gl directly, you can simply replace mapbox-gl with maplibre-gl in package.json to proceed:
Mapbox is used in services like Jetpack for the Map block as well as many plugins on WordPress.org. It is also used in WordPress.com Plugin developers who have integrated the open-source Mapbox GL JS may want to check out this library as an open-source alternative to Mapbox’s proprietary 2.0 version.