Quote Originally Posted by SirDice
IIRC "The Design of the UNIX Operating System" is about System V Release 4 (SVR4) on which Solaris is based. 4.4BSD is the base of *bsd and the 'old' SunOS.
This is kinda correct...according to the Design and Implementation of the BSD 4.4 OS, figure 1.2, Solaris 2 is derived from System V Release 4.

There is also a modern Unix v 6 clone called xv6 used by MIT in one of its courses.

It's clean code that's neat to study. It compiles on modern and runs on home PCs (instructions). I thought anyone who is reading this may be interested.