How to download and setup Qt-Widgets
Open terminal and run command
                                            git clone https://github.com/djeada/Qt-Widgets.git
                                        
                                        git clone is used to create a copy or clone of Qt-Widgets repositories.
                                        You pass git clone a repository URL. it supports a few different network protocols and corresponding URL formats.
Also you may download zip file with Qt-Widgets https://github.com/djeada/Qt-Widgets/archive/master.zip
Or simply clone Qt-Widgets with SSH
                                            [email protected]:djeada/Qt-Widgets.git                                    
                                    If you have some problems with Qt-Widgets
You may open issue on Qt-Widgets support forum (system) here: https://github.com/djeada/Qt-Widgets/issuesSimilar to Qt-Widgets repositories
Here you may see Qt-Widgets alternatives and analogs
openage tiled liteide qt qutebrowser MuseScore mapbox-gl-native qTox Clementine antimony flameshot gqrx mixxx appleseed pywebview toggldesktop edb-debugger openauto CuteMarkEd LibreCAD qgroundcontrol otter-browser feedback QDarkStyleSheet stellarium hotspot GoldenCheetah SlicerGitSVNArchive qtbase nitroshare-desktop