Wolfram Research

Wolfram Research is a company headed by Stephen Wolfram. Their primary products are Mathematica, a computer algebra system, and Wolfram Alpha, a website designed to make the world's data computable. The company also helps controversial lobbying and aids the Microsoft monopoly.

Stephen Wolfram
Stephen Wolfram is the founder of Wolfram Research.

Mathematica
Mathematica is their flagstrip product and is closed source (and proprietary). See the respective article for details.