Object-oriented programming was first developed by Norwegian computer scientists Ole-Johan Dahl and Kristen Nygaard in the 1960s through their language Simula, especially Simula 67, which introduced core OOP ideas like classes, objects, and inheritance.

Quick Scoop

Who actually “developed” OOP?

  • The origin of object-oriented programming traces back to the Simula languages (Simula I and Simula 67), created at the Norwegian Computing Center in Oslo in the 1960s.
  • These languages were designed by Ole-Johan Dahl and Kristen Nygaard to model complex systems via simulation, which led them to invent the concepts of objects, classes, subclasses (inheritance), and virtual procedures.
  • Because of this, Dahl and Nygaard are widely recognized as the original developers (or co-inventors) of object-oriented programming.

Why do people mention Alan Kay?

  • Alan Kay encountered the Simula 67 language and was heavily inspired by it when he and his colleagues designed Smalltalk at Xerox PARC in the 1970s.
  • Kay popularized the term “object-oriented programming” and pushed a very message-passing, dynamic view of objects, which is why he’s often called a “father” of OOP, though he himself credits Dahl and Nygaard for the original invention.

How it spread after Simula

  • Simula’s ideas influenced later languages such as Smalltalk, C++, Java, and many others, helping OOP become the dominant style for building large, complex software systems by the late 20th century.

Bottom note: Information gathered from public forums or data available on the internet and portrayed here.