Still interesting to see what took place in the mean time. I might end up understanding it better, if I see the evolution.
Now, from the first WordPerfect to the last, “ that is just horrible! Word Perfect was a very advanced program for its time, in the DOS world. Written in 100% Assembler. I used to have AtariST and GEM OS from Digital Research at that time with a PC emulator, that worked, but slow, so I never dared trying it. That was the closest my budget took me towards a Mac, they were rather expensive back then. Another funny thing, is that yesterday’s shelf-ware, becomes todays nerdware, because, it is not any easier to to use wordperfect, than say vi. You have to remember a lot of arcane keyboard shortcuts to be productive with it, in its original, unwindowmized form.
Totaly agree, I like to look at old code to understand things better myself. I do it still today, to know how some commands work I download the source from opensource.apple.com to understand what they are exactly doing. It’s sometimes even better than reading an manual.
Yes. At least the statements stands for the ultimate truth! (Not necessarily the comments, on a general basis.)
Please tell me, should you know something better than cscope to peruse through code with.
I am not sure if I want to look at the xnu kernel though, since I believe this to be a mess, with a Mach kernel, interwined, entangled and coexisting with CoreFoundation, IOKIt and BSD.
For the record opensource.apple.com is one of my favorite places to, for all their useful snippets. I often end up there when I google for something. And most of the time, I leave with a labor saving snippet, or something more.
Word Perfect was a very advanced program for its time, in the DOS world. Written in 100% Assembler. I used to have AtariST and GEM OS from Digital Research at that time with a PC emulator, that worked, but slow, so I never dared trying it. That was the closest my budget took me towards a Mac, they were rather expensive back then. 
Another funny thing, is that yesterday’s shelf-ware, becomes todays nerdware, because, it is not any easier to to use wordperfect, than say vi.