QGIS
Overview
QGIS (formerly Quantum GIS) is a free and open-source Geographic Information System software that allows users to create, edit, visualize, analyze, and publish geospatial information on various operating systems. QGIS is one of the most widely used open-source GIS applications.
Key Concepts
Project file (.qgz/.qgs) stores layer configurations, styles, and settings. Layer panel manages data sources and visibility. Processing toolbox provides access to hundreds of analysis tools. Plugin system extends functionality with community-developed add-ons. Print composer creates publication-quality maps.
Features
| Feature | Description |
|---|---|
| Data formats | Supports most vector and raster formats via GDAL/OGR |
| Database support | PostGIS, SpatiaLite, Oracle, SQL Server |
| Web services | WMS, WFS, WCS, WMTS |
| Analysis | Vector, raster, network, and terrain analysis |
| Scripting | Python (PyQGIS) and graphical modeler |
Core Dependencies
- OGR for data access
- GEOS for geometry operations
- PROJ for coordinate transformations
- Qt for user interface
Appendix
Created: 2025-12-13 | Modified: 2025-12-13
See Also
- Geographic Information System (GIS)
- Geospatial Data Abstraction Library (GDAL)
- Geometry Engine - Open Source (GEOS)