Objective-C, often referred to as ObjC, Objective C, or Obj-C, is a reflective, object-oriented programming language that adds Smalltalk-style messaging to C.

Today, it is primarily used in Mac OS X and GNUstep, two environments based on the OpenStep standard, and is the main language used in the foundational frameworks NeXTSTEP, OPENSTEP, and Cocoa. Generic Objective-C programs that don’t use these libraries can also be compiled on any system supported by gcc, which includes an Objective-C compiler.

ObjC was created primarily by Brad Cox and Tom Love in the early 1980s at their company, Stepstone. Brad became interested in issues of reusability in software design and programming. To demonstrate that real progress could be made, Cox argued that software components needed only a few practical changes in existing tools. Specifically, they needed to support flexible objects, have a set of functional libraries, and allow for packaging in a single cross-platform format.

The main description of Objective-C in its original form was published in Cox’s 1986 book, *Object-Oriented Programming: An Evolutionary Approach*. Cox emphasized that the problem was more about reusability than language itself, although the system is frequently compared on a feature-by-feature basis with other languages.