In the Delphi Developer group on fb, Erik Johnson provided ths very interesting, antique, snippet.
// This obfuscated pascal code worked in delphi last I tried.
// I recommend running it today or tomorrow as its message is best today or tomorrow.
// I wish I could provide credit... I found this in the 1990s as a winner of some contest for
// obfuscated pascal.
{$APPTYPE CONSOLE}
program XMas;
function t_ (t, _ : Integer; a : PChar) : Integer;
begin
if t>1 then
begin
if t<3 then
t_(-79,-13,a+t_(-87,1-_,t_(-86,0,a+1)+a));
if t<_ then
t_(t+1,_,a);
if (t_(-94,-27+t,a)<>0) and (t=2) then
if _< 13 then
result:=t_(2,_+1,'%s %d %d'#13)
else result:=9
else result:=16
end
else
if t<0 then
if t<-72 then
result:=t_(_,t,'@n''+,#''/*{}w+/w#cdnr/+,'+
'{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l+,/n{n+,/+#n+,/#;#q#n+,/+k#;*+,/''r :''' +
'd*''3,}{w+K w''K:''+}e#'';dq#''l q#''+d''K#!/+k#;q#''r}eKK#}w''r}eKK{nl]''' +
'/#;#q#n''){)#}w''){){nl]''/+#n'';d}rw'' i;# ){nl]!/n{n#''; r{#w''rnc{nl]' +
'''/#{l,+''K {rw'' iK{;[{nl]''/w#q#n''wk nw'' iwk{KK{nl]!/w{%''l##w#'' i;' +
':{nl]''/*{q#''ld;r''}{nlwb!/*df}''c ;;{nl''-{}rw]''/+,}##''*}#nc,'',#nw]''' +
'/+kd''+e}+;#''rdq#w! nr''/ '') }+}{rl#''{n'' '')# }''+}##(!!/')
else if t<-50 then
if _=Ord(a^) then begin
result:=Ord(a[31]);
if a[31]=#13 then
WriteLn
else
Write(a[31]);
end else
result:=t_(-65,_,a+1) else
result:=t_(Ord(a^='/')+t,_,a+1) else
if 0<t then
result:=t_(2,2,'%s')
else
result:=Ord((a^='/') or (t_(0,t_(-61,Ord(a^),
'!ek;dc i@bK''(q)-[w]*%n+r3#l,{}:'#13'uwloc' +
'a-O;m .vpbks,fxntdCeghiry'),a+1)<>0))
end;
begin
t_ (1, 10000, '');
Readln;
end.
Running the code results in a (possibly surprising) …
On the first day of Christmas my true love gave to me
a partridge in a pear tree.On the second day of Christmas my true love gave to me
two turtle doves
and a partridge in a pear tree.etc etc