MacOS
The Unix-like NeXTSTEP
Redwood City, California, U.S.
The Unix-like NeXTSTEP operating system was developed and then launched in 1989. The kernel of NeXTSTEP is based upon the Mach kernel, which was originally developed at Carnegie Mellon University, with additional kernel layers and low-level user space code derived from parts of BSD. Its graphical user interface was built on top of an object-oriented GUI toolkit using the Objective-C programming language.