Here's how I think it works. . .

$_="uccsm jhvkqldtr oee hofaxrtaajshkebuwelrnpitgnpry!";

#The join/sort statement turns the string into this:
#   ajbucsdte fagnhoitjhkelrm npoeprqlr shtaucvkwexry!
#This is becuase the list passed to sort is what is
#returned by the /(..)/g match; i.e., groups of two

#The print statement joins every other character, via the
#/.(.)/g statement with a newline($/); that prints out
#the desired output, i.e., just anotherp perl hacker(\n separated)
$_= join$\,sort/(..)/g and print ucfirst join$/,/.(.)/g;
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