Linux is, in essence, an operating system that represented a $25 billion ecosystem in 2008. Since its inception in 1991, Linux has become a force in computing, powering everything from the New York Stock Exchange to mobile phones to supercomputers to consumer devices.
Linux is developed collaboratively, meaning no one company is solely responsible for its development or ongoing support. Companies participating in the Linux economy share research and development costs with their partners and competitors. This spreading of development burden amongst individuals and companies has resulted in a large and efficient ecosystem and unheralded software innovation.
Over 1,000 developers from at least 100 different companies contribute to every kernel release. In the past two years alone, over 3,200 developers from 200 companies have contributed to the kernel--which is just one small piece of a Linux distribution.