QGIS – free geographic information system

Yes. QGIS is free and open source software released under the GNU General Public License; the licence text corresponds to version 2, supplemented by an exception for linking with the Qt library. When obtained from qgis.org, QGIS is free of charge; a donation is optional and not a condition for downloading.

QGIS is available from the QGIS.ORG download page. SEMPERDEAL lists QGIS for information only, does not offer it itself and is neither publisher nor partner of the project.

QGIS.ORG offers two lines: the long term release (LTR) for those who value stability over the newest features, and the latest release. Anyone who is unsure should install the LTR.

A new version is scheduled for release every four months; every third one becomes an LTR and is maintained until the next LTR. On Windows, the OSGeo4W network installer is suitable for keeping QGIS current and for running several versions side by side; the offline installers are intended for passing the download on, for example on a USB stick.

There are two ways. A single layer can be exported to any vector format that the GDAL library can write, including AutoCAD DXF, GeoPackage, ESRI Shapefile, GML, KML and CSV.

For several layers there is the DXF export of the whole project (Project menu). It lets you choose the target coordinate reference system, the encoding and the symbology mode; features can be split into several DXF layers by an attribute field, and labels are exported as MTEXT or TEXT. The settings can be saved to an XML file and reused. In QGIS, GeoPackage serves as the standard format for vector data.

According to QGIS.ORG, QGIS can be obtained for Windows, macOS, Linux, Android and iOS. The project provides desktop installation packages for Windows, macOS, Linux and BSD, as well as container images.

For field work on tablets and smartphones, QGIS.ORG refers to independent, touch-optimised third-party apps: QField (Android, iOS, Windows, macOS, Linux), the Mergin Maps mobile app (Android, iOS, Windows) and IntraMaps Roam. These apps are not published by QGIS.ORG.

Yes. QGIS supports field mapping with a connected GPS/GNSS receiver via the GPS toolbar: points are created at the current position, lines and polygons from the recorded track.

• A Bluetooth receiver is first paired with the computer and then connected via the COM port assigned to it; on Linux, connecting via gpsd is also possible.
• All incoming positions, including speed, bearing, altitude and accuracy, can be logged to a GeoPackage or SpatiaLite file, and the raw NMEA data to a text file.
• The GPS Information panel shows, among other things, HDOP, VDOP and PDOP as well as the horizontal and vertical accuracy in metres.

QGIS supports approximately 7,000 standard coordinate reference systems (CRS) defined by EPSG and IGNF, provided through the PROJ library. Layers in a different CRS are reprojected automatically into the project CRS (“on the fly”).

• QGIS uses the most accurate transformation available; if grid files are missing for it, it shows a notice and usually offers to download the package and store it in the user profile.
• A custom NTv2 file (.gsb) is placed in the PROJ folder and integrated in a custom projection via the +nadgrids parameter.
• If several transformations are possible, QGIS can ask or apply fixed defaults per pair of source and target CRS.
• The offline installers for Windows do not include the optional projection grids.