Adobe Photoshop product manager John Nack says that a 64-bit version of the Creative Suite is in the works, but it will be for Windows only. Most likely, Mac users wonit get to use 64-bit versions of Photoshop, InDesign and Illustrator until Creative Suite 5 ships.

"The development is frankly bittersweet for us: On the one hand weire delighted to be breaking new ground with Photoshop, and when processing very large files on a suitably equipped machine, Photoshop x64 realizes some big performance gains," Mr. Nack said. "On the other hand, we work very hard at maintaining parity across platforms, and itis a drag that the Mac x64 revision will take longer to deliver. We will get there, but not in CS4."

Since Creative Suite 4 for the Mac will be 32-bit only, that means Windows users will have a couple of feature Mac users wonit. Most notably, Windows users will be able to work with files larger that 4GB since the 64-bit version of CS4 will be able to access larger amounts of memory. It also means that 64-bit Windows users will about a ten percent performance improvement compared to 32-bit Windows and Mac OS X users.

The reason Mac users will remain in the 32-bit world for CS4, according to Mr. Nack, is because Photoshop and the other Creative Suite applications were written in Carbon instead of the Cocoa application framework. Since Apple decided to drop its plans for a 64-bit version of Carbon, that means Adobeis applications must be ported to Cocoa to remain on a 64-bit development path -- which will be no small undertaking.

"This means that weill need to rewrite large parts of Photoshop and its plug-ins, potentially affecting over a million lines of code, to move it from Carbon to Cocoa," Mr. Nack said.

On the surface, it could look like this is a manifestation of the alleged Apple versus Adobe feud. More likely, however, is that this is simply a situation where there isnit enough time to transition the Create Suite code base from Carbon to Cocoa in time for the CS4 launch.

In fact, Mr. Nack offers up the new public beta of Photoshop Lightroom 2 as proof of Adobeis commitment to 64-bit applications on the Mac and the companyis positive relationship with Apple. "Look, Apple and Adobe share the goal of maximizing Photoshop performance on Mac hardware, and weire working together on all aspects of that story -- 64-bit included," he said.

Mr. Nack added "As for Mac x64, weill continue working closely with Apple, just as weive been doing, to make the transition as quickly and efficiently as possible."