What Languages Fix

Haskell: there are too many experimental pure lazy functional languages.

Scala: why should you have to choose between functional and object-oriented programming?

F#: OCaml has no libraries.

Erlang: C doesn't scale.

Arc: Common Lisp is a kludge, and Scheme has no libraries.

This seems to address the reasons the languages were created more than the reasons people continue to use them today. The former is insightful, but the latter might be more useful.

This is interesting because it's a good way to look at the domain of language not in its power or application but its audience.

Haskell: Because programming isn't enough like math

Mozart: Because Prolog is pretty foreign

Lisp: Because parens are really underappreciated ; )

My favorite is "Lisp: Turing Machines are an awkward way to describe computation", especially given that McCarthy originally only intended Lisp to be used as a theoretical device, and not for actual programming! (so goes the story, anyway)

Perl: C isn't as good with text.

PHP: I'd rather write my own Perl.

Visual Basic: Crap, we desperately need a way to inflate the number of apps available for Windows.

The same is true for most companies.

PHP: Doesn't [insert other language] have that function? Let's add it, too!

Original JavaScript: HTML can't validate forms

Modern JavaScript: we are the best language committee in the world

Perl wasn't the motivation behind creating Python.

will there ever be one language to rule them all?