Have you ever used MATLAB? It's one of those languages they use/teach in the engineering dept of my uni, mainly because it's easy to write and has a good GUI-generation wizard for the programatically impaired

Unfortunately, the interpreter/IDE is written in JAVA and runs in it's own sandbox, so regardless of how much RAM you have it seems to cap out at about 256MB or so. Very annoying when you're parsing a 2mb list of country -> IP range mappings and suddenly the entire things begins to throw java errors all over because it's run out of memory in it's sandbox, even though you're using a machine with 2gb of ram

Also makes me sad in the pants when the IDE needs all of the ram Windows isn't using just to start up...
At least MATLAB supposedly installs on Linux

There's supposed to be a shell script on the first CD that acts like an installer, but of course I don't have a copy of MATLAB to try it with. (cough! cough!)
Textwrangler/BBEdit were my favourites because of their features w.r.t. regular expressions... at the time, I needed to do a perl regular expression search-and-replace on an entire hierarchy of text files (so that i could strip all the ads and sidebars and stuff from webpages i'd downloaded using wget -r) - BBEdit did it like magic

At the time, it seemed like the utterly perfect tool for text edting. (KATE does this too, actually, and you can even edit regular expressions using a gui-like thing called kregexpeditor, which helps ensure that your regular expression actually does what you meant, not what you think it meant. :p)
Note : Even if you don't use textwrangler much, you should read the section of the manual about grep/perl regexps - it's the best written introduction to PCRE's i've ever read, and if you've ever had a reason to process wads and wads of text you'll immediately see loads of uses

grep for the win!
I might download a new version of jEdit and see if it's gotten better in the last year or so. I agree that it's possibly *the* most featureful text editor in existence today, but... java? Can I stand to be near the embodiment of human sin for that long? :p