http://www.perlmonks.org?node_id=558718

"Unbalanced" because of the unmatched parentheses, braces, and brackets.  "Introspective" because ... well, you'll have to figure that out for yourself.

This works with Perl version 5.8.6 (in Linux), and 5.8.7 (in Windows), and possibly with other versions of Perl (though I can't be sure).

My apologies if this has been done before (and please let me know if so).  I came up with the idea just this evening, but one can never be sure whether or not similar prior art exists.

( $ ||= open$ ) ,$ ^X) ;; X :; { $ ;+= print if ($_ = lc getc $)) eq# } ( split$ ,,q#- just another perl hacker# ) [ $ ;]; eof$ ( ?die$ /: redo } 060630# ]

s''(q.S:$/9=(T1';s;(..)(..);$..=substr+crypt($1,$2),2,3;eg;print$..$/