Evolution of the Unix System Architecture: An Exploratory Case Study
&quot;We could not study Unix versions that derive from the Research editions via AT&amp;T System V, such as Solaris, AIX, and HPUX, because most of the corresponding code remains proprietary and inaccessible.&quot;<p>Understandable but disappointing. HPUX and AIX in particular are probably the closest thing to &quot;living&quot; UNIX time capsules.