"Carbon is and always had been a bridge of sorts to allow developers who to bring over pre-OSX apps into OSX with greater ease. The intention from Apple all along - and they did not keep this secret - was to move to an all-Cocoa environment. Carbon was the bridge that would allow easy ports of legacy code while full re-writes in Cocoa could be undertaken in the interim. Apple supported this 'bridge' for almost a full decade. Adobe had ample time to prepare and make their re-writes while still releasing in Carbon in the interim."