Everything you wanted to know about how OS X installation and licensing works...let's try to keep discussion here in this thread and I'll try to keep this first post updated with new questions and refined answers as they pop up. Keep in mind that these answers are based on what is known about the upcoming Leopard release and and how things currently work with Tiger. There are no guarantees that Leopard will be treated in exactly the same way as Tiger, so this is simply the best guess based on available information. I just bought a computer that came with Tiger installed on it. Can I upgrade to Leopard for free or at least cheaply? If you purchased your Mac on or after October 1st, you can qualify to upgrade to Leopard for US$9.95. For more details on the program, see Apple's site. Is it possible to get preinstalled Leopard on a new Mac and get a family pack (but only with 4 installs) version of Leopard for a discounted price? No. The version of Leopard that comes with your new Mac is tied to your specific model of machine and also includes the bundled software that comes with your machine. The retail version of Leopard is considered completely separate. Does OS X require a serial number or activation code in order to install on my machine? No. Simply pop in the disc and select the type of installation you want to do (upgrade, archive and install, erase and install), enter your computer's password when prompted, and let the installer do its thing. What is the "family pack?" The family pack allows you to install OS X on up to five computers that are primarily housed at a single address. Students who are away at college are also permitted to participate in a family pack in conjunction with other users at their permanent residence. From Apple's Leopard Pre-Order Page: Can unrelated roommates take advantage of a family pack? Users are not explicitly required to be members of a single family, so roommates would be able to take advantage of the family pack. Keep in mind that you only receive one disc, and should a roommate move out, they would no longer be permitted to use the OS under the family pack license. Four of my friends and I, not living in the same residence, want to split a family pack amongst ourselves. Is this allowed under the terms of the license? No. Will the family pack be available at brick-and-mortar Apple Stores at the release events (Friday, October 26th at 6 PM)? See this thread for discussion of the topic, but your best bet appears to be calling your local Apple Store ahead of time to check. Will Apple know if I violate the terms of the license? Probably not. In the case of Tiger, there are no serial numbers that need to be entered, and the software does not contact Apple to verify licensing. So why should I adhere to the licensing terms? In short, because you agree to do so in purchasing the software. Apple relies on the honesty of their users to use the software in accordance with the terms. Users are rewarded with a very simple installation process and no worries about problems reinstalling the software on the same machine whenever necessary. What are the penalties for violating the license terms? Violating the terms of a software license in not a criminal offense, so you won't be going to jail. It is, however, a civil matter, and should Apple discover the license violation and decide it was worth pursuing in a court of law, they could certainly do so and attempt to recover damages from you. While the likelihood of this occurring is extremely low, it is not zero, so it is something you should be aware of. Widespread license violations also increase the chances that Apple will be forced to turn to Microsoft-style activation in the future, inconveniencing all users. So please, for your conscience and for the benefit of all users, stick to the terms of the license.