OS X Apps and Metrowerks
This MacWeek article brings up some good points about Metrowerks influence on Apple's Mac OS X development.
A smooth transition to Mac OS X is not just in Apple's hands. Metrowerks, which commands 90 percent of the market for developer tools on the Macintosh with its CodeWarrior product, has nearly equal responsibility.
Indeed - in fact, many might recall that (at that time) relative newcomer Metrowerks was a significant player in the PPC application migration when the PowerMacs were introduced. It seems Metrowerks will be supporting only Carbon tools - while Apple will be the sole player for Cocoa (full Mac OS X) tools (for now).