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check out xlr8yourmac for more info, but without modifying device support files you won't be able to use the drive with iTunes, iDVD or DiskCopy, and you won't be able to burn from the Finder. I'd go with another brand.
 
Get the Pioneer

The original "SuperDrive" is a Pionner. I suggest you pick up the DVD-R 105. It worked on my old G4 500 tower without a glitch. There is a newer version: the DVD-R 106 that has both DVD-R and DVD+R support, but I don't know if your MD G4 will take that, so stick with the 105: I assure you it will work if you are careful with the installation.
 
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