Richard Stallman is something of a legend in the global software community. In 1983, he created the free software movement, through which highly trained and often highly paid professionals give their time to producing software for the public good.
The movement produced the GNU operating system, a free alternative to proprietary software such as the Microsoft or Apple operating systems. GNU is a both a humorous “recursive acronym” standing for “GNU is Not Unix”, and a gnu (or wildebeest) is the mascot of the GNU system and GNU Project.