After installation, add the bin folder of your chosen compiler to your Windows System Path. This allows you to run Qt tools from the command line. The Open Source Advantage
You don't need everything. Select the compiler that matches your setup (e.g., MinGW 8.1.0 or MSVC 2019).
Because it has been around for years, the community support, StackOverflow answers, and plugin availability are unmatched. Understanding the "x86" Designation
Most bugs present in early Qt 5 releases were ironed out by this version.
Even though most modern systems are 64-bit (x64), the installer is crucial for developers who need to maintain legacy software or ensure their application runs on the broadest possible range of hardware. Compiling for 32-bit (x86) ensures your .exe will run on both 32-bit and 64-bit Windows installations. Key Features of the Qt 5.15.2 Toolset
Qt Open Source for Windows (x86) 5.15.2: The Essential Guide
The lightweight yet powerful IDE specifically designed for Qt development.
A tool that simplifies the translation of your app into multiple languages.