Give my Dad the source code to Word and he won't be happy. Give him a running program and he will be (at least, as happy as anybody can be with a copy of Word ;-) Source code is not a product

That is an old, but fundamentally flawed argument. The fact that the source might need to be compiled into a different language (machine language instructions) to be used as intended doesn't mean the source isn't the product. The source code for the Parrot virtual machine isn't a specification of that virtual machine, it is an implementation of that virtual machine. Knuth's TAOCP volume I *specifies* a MIX machine without implementing one. It could be implemented in Perl, C, or even in hardware. And if I write MIX machine code that implements SomeApp, that machine code is my source code for SomeApp. The fact that the SomeApp's source code happens to be directly executable on a physical MIX machine, but is ultimately translated down to a completely different machine code when run on my Perl or C based virtual MIX machines, doesn't make that source code a final product in the first case, and just a specification or design document in the second case.