A Magnetized Needle and a Steady Hand
It's interesting to compare with DOS, where a do-nothing program is a single byte:<p><pre><code>    C3
</code></pre>
A Hello World is roughly 20 bytes, the bulk of it being the string itself:<p><pre><code>    95 BA 07 01 CD 21 C3 48 65 6C 6C 6F 20 77 6F 72 6C 64 21 24
</code></pre>
The ELF in the article, which is 130 by my count, could be reduced to 45 with some tricks:<p><a href="http://www.muppetlabs.com/~breadbox/software/tiny/teensy.html" rel="nofollow">http://www.muppetlabs.com/~breadbox/software/tiny/teensy.htm...</a><p>Also worth looking at is what the demoscene has done with binaries of 128 bytes or less:<p><a href="http://www.pouet.net/prodlist.php?type%5B%5D=32b&type%5B%5D=64b&type%5B%5D=128b&page=1" rel="nofollow">http://www.pouet.net/prodlist.php?type%5B%5D=32b&type%5B%5D=...</a>