Here is one in A+ (an APL - http://www.aplusdev.org).

By default A+ uses an APL character set but it can use ASCII as well...

$mode ascii
while (1) drop "hello world"

Another way to write it with the default character set but avoiding the drop symbol (down arrow) is:

while (1) sys.write{1;"hello world\n";12};

Of course we'd like to assign the string to a variable and use the variable and the count (#) of the variable but that would require an assignment (left arrow) symbol in the APL character set.

A gif of the same program in the APL character set available upon request (ha).

submitted by: Brian Redman