The WiX Toolset is an open-source software tool used for creating Windows installation packages. It allows developers to build installers from XML source code, making it easier to manage complex installations. The toolset is widely used for deploying applications on the Windows operating system. WiX stands for Windows Installer XML, and it provides a set of tools that integrate with Microsoft Visual Studio. This enables developers to create reliable and customizable installation experiences for their software products. The WiX Toolset supports various features, including user interface customization and support for different installation scenarios.