As if just attempting Intercal programming wasn't infamous enough, some people actually venture far enough out of the realm of the sane to produce code that actually does something. Here's the ROT13 by Jacob Mandelson, jlm@cco.caltech.edu:

(10) PLEASE DON'T GIVE UP
(1) DO .2 <- '?.1$#64'~'#0$#65535'
DO .2 <- '&"'.1~.2'~'"?'?.2~.2'$#32768"~"#0$#65535"'"$".2~.2"'~#1
DO .3 <- '?#91$.1'~'#0$#65535'
DO .3 <- '&"'#91~.3'~'"?'?.3~.3'$#32768"~"#0$#65535"'"$".3~.3"'~#1
DO (11) NEXT
DO (2) NEXT
DO (12) NEXT
(11) DO (13) NEXT
PLEASE FORGET #1
DO (12) NEXT
(13) DO (14) NEXT
PLEASE FORGET #2
DO (12) NEXT
(14) DO STASH .1
DO .1 <- .3
DO (1000) NEXT
DO .1 <- .3
DO .2 <- #1
PLEASE DO (1000) NEXT
DO RETRIEVE .1
PLEASE RESUME .3
(12) PLEASE FORGET #1
DO .2 <- '?.1$#96'~'#0$#65535'
DO .2 <- '&"'.1~.2'~'"?'?.2~.2'$#32768"~"#0$#65535"'"$".2~.2"'~#1
DO .3 <- '?#123$.1'~'#0$#65535'
DO .3 <- '&"'#123~.3'~'"?'?.3~.3'$#32768"~"#0$#65535"'"$".3~.3"'~#1
PLEASE DO (15) NEXT
PLEASE DO (3) NEXT
DO (16) NEXT
(15) DO (17) NEXT
PLEASE FORGET #1
DO (16) NEXT
(17) DO (18) NEXT
PLEASE FORGET #2
DO (16) NEXT
(18) PLEASE STASH .1
DO .1 <- .3
DO (1000) NEXT
DO .1 <- .3
DO .2 <- #1
DO (1000) NEXT
PLEASE RETRIEVE .1
PLEASE RESUME .3
(16) PLEASE FORGET #1
DO RESUME #1
(2) DO .2 <- #65
DO (1010) NEXT
PLEASE .1 <- .3
PLEASE .2 <- #13
DO (1000) NEXT
DO STASH .3
DO .1 <- .3
DO .2 <- #26
DO (1040) NEXT
DO .1 <- .3
DO (1030) NEXT
DO .2 <- .3
DO RETRIEVE .3
DO .1 <- .3
DO (1010) NEXT
DO .1 <- .3
DO .2 <- #65
DO (1000) NEXT
DO .1 <- .3
DO RESUME #1
(3) DO .2 <- #97
DO (1010) NEXT
DO .1 <- .3
DO .2 <- #13
DO (1000) NEXT
DO STASH .3
DO .1 <- .3
DO .2 <- #26
DO (1040) NEXT
DO .1 <- .3
DO (1030) NEXT
DO .2 <- .3
DO RETRIEVE .3
DO .1 <- .3
DO (1010) NEXT
DO .1 <- .3
DO .2 <- #97
DO (1000) NEXT
DO .1 <- .3
DO RESUME #1
DO COME FROM (10)
DO .4 <- #0
DO .5 <- #0
DO STASH .4 + .5
DO ,1 <- #1
DO COME FROM (33)
DO WRITE IN ,1
DO .1 <- ,1 SUB #1
DO (31) NEXT
PLEASE DO .6 <- #1
PLEASE DO (34) NEXT
(32) PLEASE RESUME '?.1$#256'~'#256$#256'
(31) DO (32) NEXT
DO FORGET #1
DO .6 <- #0
PLEASE DO (34) NEXT
(33) DON'T GIVE UP
(34) DO .6 <- "?!6'$#1"~#3
DO (40) NEXT
DO GIVE UP
(40) DO (41) NEXT
PLEASE FORGET #1
DO (42) NEXT
(41) DO RESUME .6
(42) DO FORGET #1
DO RETRIEVE .4
DO .2 <- .4
DO (1000) NEXT
DO .4 <- .3~#255
DO .3 <- .4
DO STASH .4
DO .1 <- .3
DO (1) NEXT
DO .3 <- !1~#15'$!1~#240'
DO .3 <- !3~#15'$!3~#240'
DO .2 <- !3~#15'$!3~#240'
DO .1 <- .5
DO (1010) NEXT
DO .5 <- .2
DO ,1 SUB #1 <- .3
PLEASE READ OUT ,1
PLEASE RESUME #1

Log in or registerto write something here or to contact authors.