Hannah

Hannah is a two-dimensional esoteric programming language invented by Marz. It is believed to be Turing complete.

A description of Hannah can be found here(dead link), and some examples can be found here (dead link).

Examples

Hello, world!

This program outputs the ASCII for "Hello, world!" in binary.

hello world
 v  v    vv  v v vv vv   vv vv   vv vvvv  v vv    v      vvv vvv  v    v
oooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo

Cat

This program outputs input bytes until it reaches a null.

cat
 v
xv< <  < <  < <  <
 /////////////////
v  v v  v v  v v  v
i  i i  i i  i i  i
/oo/ /oo/ /oo/ /oo/