The Mac OS X operating system grew out of the NeXT environment's combination of UNIX heritage and the Mach microkernel. Today it is one of the most widely used UNIX-like operating systems in the world. UNIX users will find a familiar environment in Mac OS X. Mac OS X contains the expected complement of UNIX utilities, contributed by programmers around the world, including many of the tools developed as part of the GNU Project. Apple is committed to the continued development of the system. With many commercial software packages available to run on Mac OS X, it is clear that the system has evolved into a serious competitor, both to other desktop environments, such as classic Mac OS and Windows, and to server and workstation UNIX systems.