jrsoftware.org
Inno Setup is an open-source installation builder for Windows applications by Jordan Russell and Martijn Laan. It supports Windows releases since 2006, 64-bit and Arm64 applications, administrative and non-administrative installs, and creation of a single EXE for online distribution. Features include file compression, shortcuts, registry and .INI entries, multilingual installs, and silent install and uninstall. Full source code is available on GitHub.