NEXTSTEP
NextStep, also branded NEXTSTEP, was an object-oriented, Unix-based operating system and development environment developed by NeXT Computer for its workstation hardware in the late 1980s and early 1990s. It combined a Mach-based kernel with a BSD-derived userland and a rich graphical user interface, offering an integrated environment for software development and execution.
NextStep introduced Interface Builder, an early GUI builder that allowed developers to design user interfaces visually
OpenStep was a cross-platform specification that extended NextStep beyond its original hardware, with collaboration from Sun
Impact and legacy: NextStep is widely regarded as influential in the design of modern operating systems and