I second what gruseom says: K (and Q, the newer version of K) is amazing. J seems more theoretically satisfyingly mathy to me, but K is a straight-up hacking la

I second what gruseom says: K (and Q, the newer version of K) is amazing. J seems more theoretically satisfyingly mathy to me, but K is a straight-up hacking language. It's really too bad that it's closed and oh-so expensive (but since it was made for real-time stock trading, and it works, I'm not surprised). Here's a good intro, by Arthur Whitney himself: http://www.vector.org.uk/archive/v101/whitney101_74.htm http://www.vector.org.uk/archive/v101/whitney101_74.htm