Linus Torvalds server where the kernel was first hosted for download, named Torvalds's directory "linux". As of 2006, approximately two percent of the Linux kernel was written by Torvalds himself. Because thousands have contributed to the Linux kernel, this percentage is one of the largest contributions to it. However, he stated in 2012 that his own personal contribution is now mostly merging code written by others, with little programming. Torvalds retains the highest authority to decide which new code is incorporated into the standard Linux kernel. Torvalds holds the "Linux" trademark and monitors the use of it, chiefly through the Linux Mark
Operating system existing hardware production. MCP is still in use today in the Unisys ClearPath/MCP line of computers. UNIVAC, the first commercial computer manufacturer, produced a series of EXEC operating systems. Like all early main-frame systems, this batch-oriented system managed magnetic drums, disks, card readers and line printers. In the 1970s, UNIVAC produced the Real-Time Basic (RTB) system to support large-scale time sharing, also patterned after the Dartmouth BC system. General Electric and MIT developed General Electric Comprehensive Operating Supervisor (GECOS), which introduced the concept of ringed security privilege levels. After acquisition by Honeywell it was renamed General Comprehensive Operating System (GCOS).