Inno Setup is an open-source installation builder for Windows applications that creates reliable software installers for deployment to end-user machines.
The tool addresses the need to package and distribute Windows applications with a professional installer experience. It works by compiling a script-based configuration into a self-contained executable installer that handles file copying, registry modifications, shortcuts, and other deployment tasks. The approach centers on declarative scripting rather than graphical configuration, allowing developers to version control and automate their installer definitions.
Inno Setup suits developers and organizations building Windows desktop applications of any scale who want to avoid reinventing installer infrastructure. It is particularly valuable for projects that need to support both 32-bit and 64-bit architectures, handle complex installation scenarios, or maintain consistent deployment across many releases. The tool has been in production use since its introduction and remains actively maintained as a mature alternative to commercial installer builders.
Development of the project involves ongoing maintenance of the Pascal codebase with compilation performed under Delphi. The source repository accepts contributions through pull requests against topic branches. Build infrastructure is provided through batch scripts that support both the free Community Edition of Delphi and commercial versions, with separate workflows for command-line and IDE-based compilation. The project maintains custom component units for UI elements that developers must install if they intend to modify installer forms, though code-only changes do not require this setup step.
