The first time I saw the C version of this, I was amazed. It was my first experience with obfuscated code in any language.
Here's my attempt at a Perlish version:
sub __{$_[0]=~y-=#&!~_`'.+,/<>():;?- .,eintsrahgldmfopv-;print@_}
sub _{($,,$:)=split/=/,$_[0],2;$* =$*?"$:$*":$:;__
"O_=`,!=$,=>+y=:)=C,r~'`(+'=(y=`.u!=<:?!=/+?!=`:=(!$/$*#$/$/"}map{_$_
}")~.'`=+=;+.`.~>/!=~_=+=;!+.=`.!!","'!c:_>=`w:=`u.`<!=>:?!'=+_>="
,"`,~.>=`,.!!=).!_c,=,!_'&=","):u.`,=):u.=c+<<~_/=b~.>'&$/"
,")~)`,=)~?!=/:<>!_=.~_/'&=","'~x`,='~x=/!!'!=+-<+y~_/&="
,"'!?!_`,='!?!_='w+_'=+-'w~((~_/&$/","!~/,`,=!~/,`=(+~>'=+-(~<k~_/&="
,"_~_`,=_~_!=<+>~!'=>+_c~_/&=","`!_`,=`!_=<:.>'=+-<!+;~_/&$/"
,"!<!?!_`,=!<!?!_=;~;!.'=;~;~_/&=","`w!<)`,=`w!<?!=>.u((!.'=>.u((~_/&=
+"