Ultimately it comes down to sematics but I think of DNA as source code. DNA is already human-comprehensible. The organisation of genes within the sequence is ac

Ultimately it comes down to sematics but I think of DNA as source code. DNA is already human-comprehensible. The organisation of genes within the sequence is actually fairly straightforward and probably not that different from how you would invent it from first principles given the constraints of the storage medium. We can routinely mix and match existing sequence components with predictable consequences. There is no need to invoke a higher level of abstraction than this. I would say that the object code is the set of RNAs present in the cell and the program is the state of all of the macromolecules in the cell - proteins, lipids, carbohydrates etc. Essentially the program is running on the organic chemistry virtual machine. When it comes to 'writing' artificial DNA the complexities are that firstly we do not understand the intricacies of how genes are turned on and off, although there is not reason that we should not come to understand this. This is the area that I am working in. The second major problem is that we cannot 'invent' new proteins as we do not how to predict the 3D shape and chemical behaviour 'folding' from the protein sequence. With massive increases in computational power and clever algorithms it is possible that this difficulty will be overcome.