A Perl program which prints "Just another Perl hacker" using extremely obfuscated methods, typically ones based on obscure behaviours of sometimes rarely-used functions, in the spirit of the Obfuscated C Contest.
The obfuscation can result from the code being total gibberish, e.g.:
$_="krJhruaesrltre c a cnp,ohet";$_.=$1,print$2while s/(..)(.)//;
or from having "Just another Perl hacker" embedded in opaque code:
$_='987;s/^(d+)/$1-1/e;$1?eval:print"Just another Perl hacker,"';eval
or from looking like it does something simple and completely unrelated to printing "Just another Perl hacker":
$_ = "wftedskaebjgdpjgidbsmnjgc"; tr/a-z/oh, turtleneck Phrase Jar!/; print;
This phrase was popularized by Randal L. Schwartz, who created most of the first such programs in the signatures of his postings to the Usenet newsgroup comp.lang.perl (the predecessor to the modern comp.lang.perl.misc).
See also: Obfuscated Perl contest