QGIS (outside page; opens in new tab); ACCESS QGIS USER MANUAL HERE.
QGIS has a user-friendly interface and useful tools. It is a well-respected organization and the leading open source GIS software (based on our opinion and many sources online). GIS Ag Maps has used QGIS for different purpose for many years. QGIS supports many file types and allows spatial data to be viewed, processed, and analyzed in different ways. Overall, it is a very user-friendly and useful program. We scan the software with Webroot SecureAnywhere (well-respected) antivirus software prior to making it available for download here.
4/26/17 - THE MOST RECENT 64-BIT VERSION OF QGIS THAT DID NOT HAVE MALWARE DETECTED WITH WEBROOT HERE CAN BE DOWNLOAD THROUGH THE LINK THAT FOLLOWS (THIS IS NOT THE MOST RECENT QGIS VERSION, BUT THE MOST RECENT VERSION WE SCANNED WITH WEBROOT AND IS QUITE RECENT):
Information About Potential Malware & Information Showing QGIS is Clean - Please Read Below
In the past, during the process of installing many versions of QGIS, we noticed that Webroot SecureAnywhere identified a potentially unwanted application (Pua) that was considered possible malware - specifically, Pua.Downloadmanager (see graphic below). While we should report this, we feel it is very unlikely that this is problematic (but are not experts in these matters). There are details about this included below. It is important to note that QGIS is well-thought of organization and has a vast amount of users (estimated hundreds of thousands of users and contributers around the world [QGIS, 2016]). In fact, Webroot reports that, while it could certianly be an issue: "The problem from an Anti-Malware point-of-view stems from the fact that many of these types of PUA applications could have legitimate uses for some people who choose to install the software (Webroot, 2013)". However, we do have a quite recent verion of QGIS that DID NOT HAVE the Pua detected by Webroot that can be downloaded from the link near the top of the page. The download version is for a 64-bit operating system - we do not have a 32-bit version (to check a computers operating system in recent versions of windows, right-click in the lower left hand corner of the screen, then click system; if this does not work, simply look up the process on-line for your computer). Or, you can download the most recent version of QGIS (which, as of April 2017, QGIS Version 2.18.6, did have the Pua for both the 32 and 64-bit versions) - it's your choice.
Information About a Potential Malware Detection in Recent QGIS Installations
Potential Malware Detection Information: In April, 2017, QGIS Version 2.18.6, QGIS Standalone Installer 32-bit and 64-bit versions showed a potential malware detection described below - this was also detected in many previous versions. Keep in mind, QGIS is a well-respected organization with a large number of users and this is likely not a problem or can be easily explained. Nevertheless, we have included the most recent version that did not show the potential malware (QGIS Standalone Installer Version 2.18.2, 64 bit) as a download from a page on this website (can be accessed through link above; version was downloaded and installed on December 20, 2016 and Webroot DID NOT DETECT ANY PROBLEMS, including the malware shown below).
The potential malware is a Pua.Downloadmanager (Potentially Unwanted Application; described on numerous site on internet). The image below shows what was identified by Webroot SecureAnywhere. The image is for a previous QGIS version, but a similar Pua warning appeared for the most recent version as of April 2017 [Version 2.18.6]).
Information Showing QGIS is 100 Percent Clean
The detection above is somewhat confusing, considering information accessed below shows that the software is 100 percent clean. Testing was made available on the popular website, www.LO4D.com, (opens to new tab that shows QGIS testing results) and showed found that QGIS is clean in all its tests. See the images below.
References
QGIS. 2016. QGIS website blog posted in 2016; cited at: http://blog.qgis.org/2016/04/23/promoting-and-using-qgis-for-the-enterprise/
Lo4D.com. 2017. Lo4D.comhttp, QGIS testing. Cited at: //quantum-gis.en.lo4d.com/virus-malware-tests
Webroot. 2013. Webroot Threat Blog. Potentially Unwanted Applications and You. Cited at: https://www.webroot.com/blog/2013/08/05/potentially-unwanted-applications-and-you/