That's why I think software is a poor analogy for DNA.
What?! Not only is human software a good analogy for DNA, but DNA is genetic programming!
Gene's are subroutines. Likewise, A, C, G, and T bases are the Base 4 equivilent to human 0's and 1's for our Base 2 (AKA "binary") systems. Re-sequence either and you can get different organisms, features, or programs, respectively.