Linux is a free and open-source and interchangeable operating system and some associated utilities and applications. It has the largest installed base of any operating system in the world today, with only supercomputers outranking it, holding onto about 80{2af4a453a258eec5af3832abf0fbfcf9638fecdaad8cda3013af19986bd37f50} of the server market share on servers - what is more, it has reached around 18{2af4a453a258eec5af3832abf0fbfcf9638fecdaad8cda3013af19986bd37f50} of world's desktops (according to NetMarketShare). Linux was first released in 1991 by Linus Torvalds.