Secure Unix ancestor KSOS did type safety before Rust made it cool

For the first time, the source code of KSOS, backed by the US Department of Defense in the late 1970s and 1980s, is available ...
InfoWorld

SGI compares Linux, Unix source code

An open letter to the Linux community published this week by Silicon Graphics indicates that SGI has conducted a comprehensive comparison of the Linux kernel and the Unix System V source code owned by ...