Created by Syntrillium Software Corporation, one of the best, if not the best, pieces of digital audio editing software available for Microsoft Windows/x86 computers. It supports many, many digital audio formats (wav, aiff, iff, etc.), many time domain and frequency domain transformations (Phase Vocoding, noise reduction, normalization, convolution, the list goes on..), data analysis, and .. well, it's very featureful.
It's sort of like Sox, SoundHack, and CSound, all rolled into one. (well, the "CSound" thing is pushing it, seeing as CSound basically does "everything".) And happily, it looks like Syntrillium provides free upgrades to the software - if you purchased Version 1.0 (in 1996 or so), you can download Version 1.2 today, for free!
All that, and it's only $399! ("only".. Well, I just bought a copy from www.bsiusa.com, for $350, but haven't recieved it yet - they billed me for, and subsequently sent me Cool Edit 2000 instead. However, now that I've been complained, they should be sending me the real thing, and they're letting me keep CE2000, too - what a deal!)