A very nice piece by CNET's David Becker on the relationship between Apple Computer and Adobe Systems Inc.. Both companies are richer because of each other's existence. Adobe committed early to the Macintosh platform and always made sure that updates of applications like Photoshop were out on the Mac platform before they were on Windows. When Apple CEO Steve Jobs announced that that Apple would make the big jump from Mac OS 9 to the Mac OS X, a lot of observers wondered if that was such a good idea. That's because the code base for OS X, based as it is on a Linux kernel, was so radically different from OS 9 that Apple would be asking all its developer partners to re-code, at great expense, its Apple applications.
Luckily for Apple, Adobe was right there as an early adopter and backer of OS X and other developers took their cue from Adobe.
Similarly, Apple built machines that exploited all the great software innovations pioneered by Adobe co-founder John Warnock, notably the early adoption of the PostScript printing language. Apple's computers, displays, and printers were among the earliest and best to render digital typefaces the way Warnock conceived of them. Apple's commitment to help realize Warnock's vision helped Adobe.
But now, to use Becker's metaphor, the relationship between Apple and Adobe is like any marriage that's lasted 20 years:

They share an area code, a customer segment and a history dating back to the early days of personal computing. But Apple Computer and Adobe Systems, like many in long-term relationships, have seen the 20-years-and-counting bond between them run hot and cold.
Right now, it's in a colder period. Signs of frost have been accumulating for the past couple of years, with Adobe dropping Macintosh support for several software products and introducing others as Microsoft Windows-only applications. At the same time, Apple has quietly pushed Adobe out of a few markets by selling its own applications or bundling them into its OS X operating system.