C Preprocessors evil behavior

I can't believe that most C compilers can compile such a obfuscated code.

http://gist.github.com/98042

%:include /\
\
*\*\*\*\*\*\*\
konyanyachiwa!
*\*\*\*\*\*\*\
/ <stdio.h>
 
int ma\
in (a,b)
int a;
char b
<::><::>;<%
puts("Hel""lo,\
 world!");
return 0;
%>