Fastest prototyping language?

I want to write programs as fast as I can. Which language should I learn?

Using program length as a rough indicator, Forth is the choice. Samples I've seen like web servers, operating systems, database managers, etc. are significantly shorter in Forth.

But I've seen some really short Perl and Haskell routines too.

And Lisp is supposed to allow you to work at such high levels of abstraction that it should also make short applications.

Ruby gets a lot of comments about short line counts compared to Perl and Python.

Assuming
   -identical toolset library functionality,
   -maximum expertise in all the candidate languages
   -no concern of readability, "transparent" design, or 
    execution speed
which language syntax will allow you to write your program fastest?

In b4 machine code.

It seems to be the natural life cycle. Lisp is the second oldest programming language after FORTRAN. I gather that it did have strong leaders who are retired or dead now. Perl is the elder "scripting" language, and Larry Wall has slowed down and yielded to the dreaded committee, hence the rise of Python and Ruby and their young turk leaders.

Back to the practical matter of Fastest Prototyping Language I should Learn Right Now: here's what I'm focusing on:
**3 Families of Languages. The S-expression family includes Lisp and Scheme and intersects substantially with Python/Ruby/Perl. The stack-based family includes MANY Forths and extended Forths like Factor. The ML family includes Haskell and Caml. Of these 3 families, the S-expression seems best for fast prototyping because it's flexible and malleable. The others seem to require you to go back and start from the beginning when you want to make a substantial change. Scheme is the simplest in the S-expression family, so I'm starting there to get my mindset. plt-scheme.org is the best looking intro I've found.
**FFI. Many interpreters use libffi to let you call regular .a and .dll libraries, making the C and C++ standard libraries available to you. I'm coming from C and I know those libraries well. If the interpreter (byte code compiler for you precision fags) lets me call into user32.dll and put some windows on the screen, then I'm in my home territory.
**CPAN. A huge, centralized repository of finished routines, tested and indexed. You can plug them into your project or use them as examples. I don't know if any of the other languages have surpassed Perl's CPAN yet. Although I will write my top control logic in Scheme or whatever, I will look for a way to call Perl and pass data to and from it, even if I have to use files to make that work.

There are counter-arguments. You can get so good at Haskell or Forth that you get your program mostly right the first try and end up with tiny, elegant code. I don't think I'll ever be that smart, though. The Lisp hacking philosophy suits my stumbling idiot, one-little-step-at-a-time approach better.