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 and connect them to code. The system used the Objective-C language and a layered set of frameworks, notably Foundation and AppKit, which provided object-oriented libraries for data handling, UI components, and event processing. Graphics and windowing were handled by Display PostScript, enabling scalable rendering of the GUI.

OpenStep was a cross-platform specification that extended NextStep beyond its original hardware, with collaboration from Sun Microsystems. Apple later acquired NeXT in 1996 and refashioned the technology into macOS. The Objective-C/NeXTSTEP-based frameworks evolved into Cocoa, the primary API for macOS, and later formed the basis for Cocoa Touch on iOS.

Impact and legacy: NextStep is widely regarded as influential in the design of modern operating systems and software development environments, particularly for its integrated development tools and object-oriented frameworks. Its history reflects a key transition from proprietary workstation ecosystems to widely used consumer platforms.