In Object-oriented programming (OOP), sets of data and instructions are collected into self-sufficient packages called "objects". The sets of instructions are combined with routines (called methods) to produce a desired outcome. OOP is very versatile, especially in comparison to its predecessor, procedural programming, which required that instructions be written in sequential order.
Object-oriented programming, which was developed around 1970, can be used very effectively with programs such as the ones that display the date and time on your computer screen.
Smalltalk, C++, Object Pascal, Eiffel, Self, Loops, Dragoon, BETA, Emerald, POOL, and ESP.