I knew most of them but not all. However as he targets OSX users, I suspect many of the programs are unknown to them.
Converseley, there are plenty of long-term unix experts out there who also find that a mac makes a nice workstation that still satisifies their need for unix tools plus other stuff.
Edit: looking at the site again, at least one of those screenshots is from OS X. htop lists /sbin/launchd and several processes from /Library/Frameworks.
And it was easiest to take the screenshots from my OS X laptop. For some tools, like powertop, I had SSH-d into various Linux or FreeBSD boxes.
Some of these are uncommon enough that they are not ported to every package manager system, too. :(