It wasn't fully FOSS till 2021: > The Inferno Business Unit closed after three years, and was sold to Vita Nuova Holdings. Vita Nuova continued development and

It wasn't fully FOSS till 2021: > The Inferno Business Unit closed after three years, and was sold to Vita Nuova Holdings. Vita Nuova continued development and offered commercial licenses to the complete system, and free downloads and licenses (not GPL compatible) for all of the system except the kernel and VM. They ported the software to new hardware and focused on distributed applications. Eventually, Vita Nuova released the 4th edition under more common free software licenses, and in 2021 they relicensed all editions under mainly the MIT License. [1] [1] https://en.wikipedia.org/wiki/Inferno_(operating_system) https://en.wikipedia.org/wiki/Inferno_(operating_system)