Kernel (operating system) obsolete by virtually all operating system researchers. As a result, the design of Linux as a monolithic kernel rather than a microkernel was the topic of a famous debate between Linus Torvalds and Andrew Tanenbaum. There is merit on both sides of the argument presented in the Tanenbaum–Torvalds debate. Monolithic kernels are designed to have all of their code in the same address space (kernel space), which some developers argue is necessary to increase the performance of the system. Some developers also maintain that monolithic systems are extremely efficient if well written. The monolithic model tends to be more efficient
Security-evaluated operating system in August, 1987. The Unisys OS 2200 operating system includes an implementation of the DoD Orange Book B1, Labeled security protection level specification. OS 2200 first obtained a successful B1 evaluation in September, 1989. Unisys maintained that evaluation until 1994 through the National Computer Security Center Rating Maintenance Phase (RAMP) of the Trusted Product Evaluation Program. Security-evaluated operating system In computing, security-evaluated operating systems have achieved certification from an external security-auditing organization, the most popular evaluations are Common Criteria (CC) and FIPS 140-2. Trusted Solaris 8 was a security-focused version of the Solaris Unix operating system. Aimed primarily at the