There's having An honorary degree... and then there's having 6 of them plus numerous other awards, and all the achievements to back them up :)

Regardless, I've met people with only honorary doctorates, and it's a mixed bag when it comes to preferred titles. Often, though, the ones that really care, soon acquire a 'superior' title anyway, so it ends up becoming a moot point.

I was adding Go to the list at the very end of the comment:

>OpenMP also inherits many of those concepts, and some of them are also in CUDA.

"Sir", not "Mr." if you're going to be pedantic about titles ;)

Edit: Oh and he has multiple honorary doctorates (at least 6!), so would be just as much "Dr." too!

And, of course, the Go programming language.

Further Reading for the curious:

On specifically the relationship between Occam and Transputer architecture: http://people.cs.bris.ac.uk/~dave/transputer1984.pdf

Wider reading: http://people.cs.bris.ac.uk/~dave