Digidesign's Pro Tools
The Most Popular Music Recording Program Around The World.
ProRemote 0.01
Here's a cool 3rd party application that Pro Tooler's can look forward to, especially if you're thinking about getting an iPhone.
How To get Started With Pro Tools Quick, Easy, and Cheap:
Mbox 2 Micro, Mbox 2 Mini, Mbox 2, Mbox 2 Pro
The Mbox Family