Mapbox GL JS vs. Mapbox.js

Question

From the Mapbox glossary, Mapbox.js

Mapbox.js is a JavaScript library that allows you to add an your interactive map to your website. It is a plugin for Leaflet, and it is an open source library that’s free to use.

and Mapbox GL JS

Mapbox GL JS is a JavaScript library that uses Mapbox GL to render interactive maps. It’s an open source library that’s free to use. You can add a Mapbox style or a custom style created with Mapbox Studio to your Mapbox GL JS application.

and from this answer

Mapbox Styles are for use with Mapbox GL and the native iOS and Android SDK's. You can't use them with classic Mapbox JS. Mapbox JS supports raster tiles, you can't style those. They're just images. Mapbox GL and the native SDK's (can) use vector tiles and those are stylable.

I believe I can use mapbox.js as a replacement to the leaflet css and js sources, but can I do the same with mapbox-gl.js?
What other differences exist between the two libraries?

Answer 1

For developers who have experience building web maps with Mapbox.js or Leaflet, switching old projects to use Mapbox GL JS can drastically improve the performance of your existing applications. Mapbox GL JS uses WebGL client-side rendering to display your maps, which results in faster loading, smoother transitions when zooming or panning, and greater flexibility to change map data and styles on the fly. These improvements make switching to Mapbox GL JS well worth the effort, so I recently converted Peter’s Courier demo from Mapbox.js to GL