I've been experimenting with generating my own vector tiles and client-side rendering with Tangram in order to figure out how to best write a style in its language.
Tangram is a GL-based renderer written by Mapzen and normally used with their Tilezen vector tiles, but I'm interested in being able to make my own vector tiles with different cartographic choices.
Having a diverse selection of vector tile schemas is important, as is avoiding a situation where only large players in the market can get involved like right now.
For a toolchain I used osm2pgsql with ClearTables and Mapnik via Kosmtik to write vector tiles. With the demo I'm serving pre-rendered vector tiles from disk, but Kosmtik is useful in development with it's xray functionality. I input the style into Tangram Play, a web-based editor that automatically reloads the map when you change the style.
The cartography and vector tile definitions are loosely based on OSM Clear, a demo style I wrote. I didn't want to learn the language while designing new cartography at the same time. Being a learning exercise I don't consider the style complete or free of bugs.
I'm not sure what direction I'm going to take next as I don't have any particular style goals right now, or collaborators.