JsNik
JsNik is node library for generating Mapnik configuration in JS. This adds all the benefits of scripting like preventing repetition, programatic style generation, etc.
Installation
npm install jsnik
Example
Mapnik configuration in JS: https://github.com/FreemapSlovakia/freemap-mapnik/tree/master/style
Resulting map: https://www.freemap.sk/?map=10/48.725397/19.414215&layers=X