Like Mapbox, Protomaps is a full-stack, vector-based mapping solution, with basemap data, API and client-side rendering components. Mapbox is a mature, venture-backed company that provides its map data as a metered-use API; it provides a family of integrated services such as geocoding and routing, and it also develops 3D-capable, real-time map rendering libraries for the web and native platforms.
They key unique goal of Protomaps is to provide the simplest and most flexible solution for the mainstream map use case: displaying geographical data on the web. This core philosophy extends from map data - which you can host yourself - to the protomaps.js map rendering library, which is less than 30 kb and integrates seamlessly with Leaflet.
If you'd like advice choosing between different map platforms, contact [email protected].