Julia is a new upstart numerical language that I've been looking at recently. Its still very rough, not even 0.2 yet, but it has some impressive chops. As an alternative to R and MATLAB, it has a lot going for it. Much has been made in blogs and forums about the advertised speed, and whether this is hyped or not. I think this misses the point; what is important is the tradeoff of speed for expressiveness.