UEFI was created by an alliance of 12 companies, 11 of whom are not Microsoft, and Intel began the work. Again, not Microsoft. TianoCore is an open source ref

UEFI was created by an alliance of 12 companies, 11 of whom are not Microsoft, and Intel began the work. Again, not Microsoft. TianoCore is an open source reference implementation of UEFI maintained by Intel; there's no proprietary Microsoft stuff in there. Microsoft seek to ease development for users who either choose Windows or who are forced to use Windows by an employer. there's no "play" here, no extending or extinguishing. They want, like any reasonable developer would, a better world for software developers.