iOS / Windows etc are not open source and are delivered by centralized entities (Apple, Microsoft). Android is open source but is also delivered by a single com

iOS / Windows etc are not open source and are delivered by centralized entities (Apple, Microsoft). Android is open source but is also delivered by a single company (Google). Maybe my phrasing didn't reflect it but I meant one of the biggest upgrades for an open source project done by a distributed group of developers.