Quantum GIS is open source software that allows users to create and edit their own geospatial information as well as visualising it and publishing it for other people to make use of.
It is written in C++, Python, Qt and usable in Microsoft Windows, Linux, macOS and Android (beta) platforms.
QGIS also provides an OGC Web Server application, a web browser client and developer libraries. The QGIS project is under very active development by an enthusiastic and engaged developer community with good mechanisms for help via stack exchange, mailing lists and (optionally) through a global network of commercial support providers.
We found it as a useful tool to create our 2D and 3D map by adding the qgis2threejs plugin.
-Phumzile M