Go's version of the PROJ.4 projection library

A JavaScript port of the Proj.4 map projection library.

A library that converts GeoTIFFs geokeys to Proj4 string

İBB İETT Geojson API

Proj4dart is a Dart library to transform point coordinates from one coordinate system to another, including datum transformations.

OGC/GIS functions and extensions for Dremio

Proj4 extension for rgeo.

Simple Features Projection Java Library

View popular online maps in Orthographic projection

Projections iOS Library

Draw an area and export it using ogr2ogr in several formats

坐标系转换，并提供WKT linestring数据格式转换

Coordinate Reference Systems Java Library

open-source plugin loading vector tiles for geojson in proj4 coordinates

Web Application for calculating transition parameters from local coordinate systems to WGS84 with geodetic accuracy for geodesy and GIS

Custom projection (LV95) example for Leaflet

Simple Features Projection iOS Library

Projections Java Library

Coordinate Reference Systems iOS Library

Grid - a local HTTP server for generating vector tiles (in KML and GeoJSON formats) with various geographic/coordinate grids.