Identical <mapml-viewer> markup rendered by the
Leaflet build (left) and the MapLibre GL build (right). Each map runs
in its own iframe because both engines register the same custom-element
names. A more capable engine takes advantage of extra markup; a less
capable engine still renders a usable map.
Both maps declare view="globe" and
controlslist="static view" on the same plain OSMTILE layer.
MapLibre GL honours the view and static attributes,
presenting the map as a frozen 3-D globe with a view and lock control. Leaflet
ignores the attribute and controlslist token it does not understand and renders
the same content as a flat 2-D map — both engines produce a working map from the
identical markup.