Nonsense question - as it's no longer supported CS3 as it's going back to 2007 - which is like 13 years ago!
From Wikipedia:
CS3 improves on features from previous versions of Photoshop and introduces new tools. There is also improved support for Camera RAW files which allow users to process images with higher speed and conversion quality. CS3 supports over 150 RAW formats as well as JPEG, TIFF and PDF. Enhancements were made to the Black and White Conversion, Brightness and Contrast Adjustment and Vanishing Point Module tools. The Black and White adjustment option improves control over manual grayscale conversions with a dialogue box similar to that of Channel Mixer. There is more control over print options and better management with Adobe Bridge. The Clone Source palette is introduced, adding more options to the clone stamp tool. Other features include the nondestructive Smart Filters, optimizing graphics for mobile devices, Fill Light and Dust Busting tools. Compositing is assisted with Photoshop's new Quick Selection and Refine Edge tools and improved image stitching technology.
CS3 Extended includes everything in CS3 and additional features. There are tools for 3D graphic file formats, video enhancement and animation, and comprehensive image measurement and analysis tools with DICOM file support. The 3D graphic formats allow 3D content to be incorporated into 2D compositions. As for video editing, CS3 supports layers and video formatting so users can edit video files per frame.
Compatible with Intel-based Macs and PowerPCs, supporting Windows XP and Windows Vista. CS3 is the first release of Photoshop that will run natively on Macs with Intel processors: previous versions can only run through the translation layer Rosetta, and will not run at all on Macs running Mac OS X 10.7 or later.