PostGIS - Open source spatial database
Mapbox - An open source mapping platform for custom designed maps. Our APIs and SDKs are the building blocks to integrate location into any mobile or web app.
H2GIS - A spatial extension of the H2 database. Compliant, Solid, Tested.
QGIS - QGIS is a desktop geographic information system, or GIS.
ArcGIS - ArcGIS software is a data analysis, cloud-based mapping platform that allows users to customize maps and see real-time data ranging from logistics support to overall mapping analysis.
OpenStreetMap - OpenStreetMap is a map of the world, created by people like you and free to use under an open license.