Utilities & Conversion Tools

GDAL/OGR: A translator library for raster (GDAL) and vector (OGR) geospatial formats. 

PROJ: A library for performing conversions between cartographic projections. 

GPSBabel: A tool for converting and transferring GPS waypoint, track, and route data between formats. 

Mapshaper: A web-based tool for simplifying, editing, and converting GIS vector data. 

EPSG.io: An online service for discovering coordinate reference systems and converting between them.

Turf.js: An open-source JavaScript library for advanced geospatial analysis and processing. 

FME: A commercial spatial ETL platform for data conversion by Safe Software.