When I started to do StorytestDrivenDevelopment (SDD) in 2002-2003, I began to think of the storytests as being mini specifications. That naturally led to calling them "executable specifications" since we were automating them.
When I discuss ExecutableSpecifications with newbies, I often make the distinction that regular old specifications can easily get out of synch with what a system actually does. By automating the specifications, we ensure that essential system functionality behaves as its customers expect it to. --JoshuaKerievsky
A related thought: I tried to explain to an enquirer today as to how workers in an establishment might use RSS. I used the example of using it as a means of keeping up to date with the changes in governing documents which might be posted to an intranet site, such as specifications. I explained using RSS would enable the interested individuals to have a method of synchronization as to "what is going on here". -- DonaldNoyes 20070818
TheSourceCodeIsTheSpecification