In the early days of microcomputers, user interfaces were individually invented until an Apple-influenced IBM standard brought about harmony. The IBM PC legitimized microcomputers for business use in 1981, while Apple’s Macintosh made graphical user interfaces mainstream. IBM’s initiative called Systems Application Architecture influenced the design of software user interfaces for decades to come. However, this standard did not reach the Linux and Unix shell, creating a clash of cultures between the Unix and microcomputer traditions. The introduction of Windows and web apps, as well as Microsoft legal threats, further complicated the software landscape.
https://www.theregister.com/2024/01/24/rise_and_fall_of_cua/