VirtualBox software is a free and open-source virtualization tool that allows users to run multiple operating systems on a single machine. It provides support for a wide range of guest operating systems, including Windows, Linux, and macOS. The software also offers features like snapshotting, shared folders, and seamless mode, which enables users to run applications from guest systems on the host desktop. Additionally, VirtualBox allows users to create and manage virtual machines through a user-friendly interface.