GeoNode is an open source platform for geospatial data
A very fast geospatial point clustering library for browsers and Node
Python and JavaScript bindings for calling the Earth Engine API
Transform, query, and download geospatial data on the web
Your window into the Elastic Stack
An open-source JavaScript library for world-class 3D globes and maps
A modular geospatial engine written in JavaScript
Google Earth Enterprise - Open Source
OpenSearch GeoSpatial Catalogue
OSGeo project deegree