Ok, I'll admit it. I don't do all of my work in Pocket Forth alone. My second favorite language is Userland Frontier. Actually language is a bit too weak of a term for Frontier. Where as Pocket Forth is used to make applications, Frontier is used to make applications work together and work with the Mac OS better. (If you have ever used AppleScript but wished it wasn't lame, you want Frontier.)
Frontier is also free, but you can only get it from online sources. On the World Wide Web go to http://www.hotwired.com/Staff/userland/aretha/ for the software, documentation and good dose of neo-Hardenburghesque philosophy.
