The article doesn't mention any free/open-source versions of Whitney's work, but I do know of one, A+. It was extended from A, which does get a mention.

http://www.aplusdev.org/

On another note, has anyone here played with the latest and greatest, Q?

I work with it daily. Very impressive stuff generally, but the domain is highly specific. Some of the guys who work with it are really smart. Soup to nuts sort of knowledge.

Hi, do you have a blog or would you be willing to post something about your experience with Q and KDB+? I worked in the financial industry for awhile and we were pulling some data from KDB+ systems. I thought about digging deeper into Q and KDB+, but other side projects kept me from really diving in.

Maybe I'll revisit it now that they offer a free trial version.

Don't really have a blog that I update.

I do have a Github account where I've been developing some projects in Q: http://github.com/DannoHung/qspec and http://github.com/DannoHung/qutil

I'm willing to answer questions if you have any.

Octave, R, Lush, NumPy, and PDL (the Perl one) have some of the APL-nature too.

It's mostly a discussion about his variants of APL. I don't understand the reasoning behind starting from scratch every time writes a new language but he does make some interesting observations about common lisp. Interesting, worth reading.