- Modern, compiled with [Qt 5.15.9](5.15.9) for macOS 10.13+. If you do not own a commercial license, you can still use [Qt 5.15.2](5.15.2), the folder contains number of mostly macOS-related patches already applied in order to be compiled and used normally on modern macOS versions (e.g. Big Sur or Monterey). Building universal binaries for both x86_64 & Apple Silicon with Qt 5.15.2 is tricky, [but possible](https://github.com/crystalidea/macdeployqt-universal).
- Legacy, compiled with [Qt 5.6.3](5.6.3) for macOS 10.7-10.12. The folder contains several macOS-related patches ([QTBUG-40583](https://bugreports.qt.io/browse/QTBUG-40583), [QTBUG-18624](https://bugreports.qt.io/browse/QTBUG-18624), [QTBUG-52536](https://bugreports.qt.io/browse/QTBUG-52536), [QTBUG-63451](https://bugreports.qt.io/browse/QTBUG-63451) ) already applied in order to be compiled and used normally. For compilation we use macOS 10.13 and XCode 8.
To apply patches and compile Qt the same as we do, simply copy the contents of the folder ([Qt 5.15.2](5.15.2) or [Qt 5.6.3](5.6.3)) to the official Qt source tree (overwriting existing files of cause).
On Windows you need [VS2019 Community Edition](https://visualstudio.microsoft.com/downloads/) and [Perl](https://strawberryperl.com/). QtNetwork module is compiled using openssl-1.1.1k which is pre-compiled but once you delete the folder, it will be compiled again.