This paper focuses on Quantum GIS (QGIS), an open-source cross-platform application that allows to visualize geospatial data in various formats. The paper indicated the main advantages of QGIS web application (second version) – QGIS Web Client 2: free distribution; free access to open-source code, which allows to write or modify a script or program module; permission to modify the source code; the ability to install the program on various operating systems (Windows, Mac OS, Ubuntu, etc.); a large library of free modules for working with geodata; the ability to publish maps on the web using Mapserver and other analogs; the ability to download space images from different sources (Yandex, Google, Bing Aerial, etc.); the ability to post data and publish projects on the Internet using the QGIS Cloud plugin. The technical requirements for the design of the QWC2 web application are presented; instructions for installing and QWC2 configuration on the available infrastructure are also given. The testing and the functionality of QWC2 application were presented on practical examples (area / length / coordinate measurements; thumbnail / redline functionality; generation of permalinks; PDF printing; ability to export maps in different images; import WMS/WFS; map comparison).