Computer Systems Research Group

"CSRG" redirects here. For the defunct Chinese rolling stock manufacturer, see China South Locomotive and Rolling Stock Industry (Group) Corporation. For the World War I era machine gun, see Chauchat.

Simplified evolution of Unix systems. The Mach kernel was a fork from BSD 4.3 that led to NeXTSTEP / OpenStep, upon which macOS and iOS are based.

The Computer Systems Research Group (CSRG) was a research group at the University of California, Berkeley that was dedicated to enhancing AT&T Unix operating system and funded by Defense Advanced Research Projects Agency.