Paul Graham (computer Programmer) - Blub

Blub

Blub is a hypothetical programming language; it is an average language "right in the middle of the abstractness continuum. It is not the most powerful language, but it is more powerful than Cobol or machine language." It was used by Graham to illustrate a comparison of power between programming languages that go beyond Turing completeness, and more specifically, to illustrate the difficulty of comparing a programming language one knows to one that one does not:

"Our hypothetical Blub programmer wouldn't use either . Of course he wouldn't program in machine language. That's what compilers are for. And as for Cobol, he doesn't know how anyone can get anything done with it. It doesn't even have x (Blub feature of your choice).

As long as our hypothetical Blub programmer is looking down the power continuum, he knows he's looking down. Languages less powerful than Blub are obviously less powerful, because they're missing some feature he's used to. But when our hypothetical Blub programmer looks in the other direction, up the power continuum, he doesn't realize he's looking up. What he sees are merely weird languages. He probably considers them about equivalent in power to Blub, but with all this other hairy stuff thrown in as well. Blub is good enough for him, because he thinks in Blub.

When we switch to the point of view of a programmer using any of the languages higher up the power continuum, however, we find that he in turn looks down upon Blub. How can you get anything done in Blub? It doesn't even have y.

By induction, the only programmers in a position to see all the differences in power between the various languages are those who understand the most powerful one. (This is probably what Eric Raymond meant about Lisp making you a better programmer.) You can't trust the opinions of the others, because of the Blub paradox: they're satisfied with whatever language they happen to use, because it dictates the way they think about programs."

The concept has been cited by writers such as Joel Spolsky.