If you go to the Apple menu and select "About This Mac," you should get some basic information about the Mac mini you have. If you click on More Info, you'll get more details on it. Please add that information on here so that we can let you know. If it's a G4 Mac mini, then so long as it's greater than 867 MHz you should be able to install 10.5 on there without a problem. You should probably upgrade the RAM to at least 1 GB.
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