Dennis Ritchie at AT&T Bell Laboratories pioneered the C programming language in the early 1970s. However, this programming language did not begin to gain widespread popularity and support until the late was because, until that time, C compilers were not readily available for commercial use outside of Bell Laboratories. Initially, this growth in popularity was also partly spurred by the equal, if not faster, growth in popularity of the UNIX operating system, which was written almost entirely in C. Brad J. Cox designed the Objective-C language in the early language was based on a language called SmallTalk-80. Objective-C was layered on top of the C.