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 device drivers to the operating system's kernel, where they can be passed onto applications, or carried out directly. Security of operating systems has long been a concern because of highly sensitive data held on computers, both of a commercial and military nature. The United States Government Department of Defense (DoD) created the "Trusted Computer System Evaluation Criteria" (TCSEC) which is a standard that sets basic requirements for assessing the effectiveness of security. This became of vital importance to operating system makers, because the TCSEC was used to evaluate, classify and select trusted operating systems being considered for the processing, storage