I have several macs that I use at home and the office. One of them is a Quicksilver 733 with 512 of RAM. I currently have 10.4.5 and it runs acceptable as far as basic tasks: Safari, word, Excel, etc. It will run more sophisticated software, but slowly. I personally wouldn't want it for my main computer, because I use a G5 iMac at home or my new Macbook, but to experiment with it could be fun. Think about what you will want to do with it, because I had to upgrade to USB 2.0 to run a printer/scanner from it at the office. Not a large expense, but still an expense.