In 1979, Danish programmer Bjarne Stroustrup (b. 1950) started working at Bell Labs. He had previously worked using Simula67, considered to be the first object-oriented programming language. Simula67 had been designed to let people model real-world systems easily, but Stroustrup found it quite slow. He decided to add object-oriented features to C, to create a fast language for building large systems. This resulted in C++, which was released in 1983.