Damian Conway's explain-by-example followups to Larry Wall's
Apocalypses regarding the design of
Perl 6.
Usually, the two are paired, and tightly coupled. Larry will write an Apocalypse describing some new feature, or general change, reference-style, and within a while, Damian will have an Exegesis for us, chock full of examples, insights, and the general stuff that you need to use it.
This turns out to be a rather convenient way to have the information presented, in my opinion, and apparently, also a pretty good way to develop, as E$n often sparks discussion that leads to ideas that eventually make it into A$($n+1). (Yes, I'm one of those crazy folks who is actually optimistic about Perl 6.)
Damian also gave us a Synopsis once, but I think that's just because he was too busy to write E5 at the time, and everybody was clamoring.
If you want to find all of these nifty documents, "Article Archive" at www.perl.com is probably your best bet.