A better list
by Animats (122034)

We can do better than that. In no particular order,

• IBM's VM operating system. (1972) OS/360 was a nightmare, and not even the best OS of its era. Burroughs and UNIVAC were way ahead in operating systems in the late 1960s. VM, though, had paging, good security, hypervisor capability, and good performance. In the 1970s. And it's still in use.
• Backus' FORTRAN compiler (1957) The first good compiler. Optimizing, even. Better code generation than anything running on UNIX prior to the mid-1980s.
• QNX (1980) The first really good microkernel OS. Still in use, deep inside railroad signalling systems, machine tools, and nuclear reactor controls, where it has to work.
• NLS (1967) The first system with a mouse, windows, and a GUI. It took a mainframe to make it go in 1967, but all the key ideas were there.
• AutoCAD (1982) This is the program that replaced the drafting board. Huge increase in productivity. Ever ink in a drawing by hand? Redraw a drawing to make changes? Engineering companies used to have acres of people doing that stuff. No more.
• Bravo (1974) The first what-you-see-is-what-you-get text editor. Multiple fonts. Ran on the Xerox Alto. The ancestor of all modern word processors.

Those are older examples, each a major advance over previous technology. As the technology becomes more mature, the advances become smaller, but more widely deployed.