We previously reported that the Key Caps and Disk Copy applications are no longer part of OS X in Panther; Key Caps has been replaced by the Keyboard Viewer palette, and most of Disk Copy's functionality has been rolled into Disk Utility. We also reported that there are a few features of the older apps that did not make the transition. At the suggestion of a few MacFixIt readers, we copied Jaguar's Disk Copy and Key Caps to a Panther machine, and we can report that they both appear to work -- Key Caps works flawlessly, and although Disk Copy tends to quit unexpectedly from time to time, it does function fairly well. (If you upgraded to Panther from Jaguar using an Archive and Install installation, and still have the Previous Systems folder, you actually still have both apps, inside the /Applications/Utilities directory in that folder.)
More interestingly, we discovered that if you use Jaguar's Disk Copy in Panther, in addition to gaining back features lost in Panther, you are actually presented with more options than you had under Jaguar! For example, when you create a new disk image, you can choose new volume formats supplied in Panther: the volume Format choices for new images now include Mac OS Extended (Journaled) and Mac OS Extended (Case-sensitive/Journaled). In addition, you can also take advantage of the sparse image format (via the Image Format pop-up), which was available in Jaguar but only via Terminal's hdiutil command. Also, a new Image Layout menu appears when creating a new image, offering several new choices: SCSI HD, single partition, CD/DVD, no partition map, hard disk, and ATA HD. Finally, when creating an image from a folder, the Image Format menu includes several new options: compressed (ADC), entire device, UDIF stub, and a number of NDIF formats. Although from a technical standpoint this makes sense -- Disk Copy uses one of OS X's Unix commands, hdiutil for much of its functionality, and that command itself has more options under Panther than it did under Jaguar -- it's still a bit surprising that Disk Copy appears to seamlessly adapt to these new features.
As a side note, if you're curious about changes to hdiutil in Panther, the man page (manual) for the command provides the following details:
"As of Mac OS X 10.3, most Disk Copy functionality moved to Disk Utility and a new background application DiskImageMounter attaches images for the Finder. hdiutil features the new verbs makehybrid, compact, and chpass. create has undergone a number of enhancements, most notably the ability to create an image directly from a source directory. All framework clients now use the same diskimages-helper background process for processing images, including applications such as Safari."