Does OS X have authentication code like Windows??

nope

dont engage in piracy though

You "could" buy the 10.6 DVD and install it on whatever machine you want, but the proper way may be to buy the 10.5 first, hopefully someone will post the documentation that comes with the $30 10.6 DVD so we know what Apple says.

If you want to install on more then one machine you should get the family pack set. This will allow you to install on up to 5 machines. With the "Upgrade" price from 10.5 the family pack is a great deal.🙂

Your best off just buying the full family pack 10.6 package. That way you're legit.

Apple "trusts" its customer more than most companies, and because of that, there are no serial numbers to type in. If you need to install Snow Leopard on more than one computer, you should buy the family set, if only planning on installing on one, get the single user edition.

angelwatt said:

Your best off just buying the full family pack 10.6 package. That way you're legit.

Click to expand...

Oh yes, this! Just saw you had two machines, this would be the only way to be legit unless you buy two 10.5 DVDs and two 10.6 DVDs

Don't necessarily need to even go via Leopard if you're starting with Tiger, from what Mossberg hints at.

xXriderXx7 said:

Apple "trusts" its customer more than most companies, and because of that, there are no serial numbers to type in. If you need to install Snow Leopard on more than one computer, you should buy the family set, if only planning on installing on one, get the single user edition.

Click to expand...

I don't really think it has anything to do with trust. Apple makes it money from hardware sales and pro software, not OS updates. The OS is really a selling point for the premium-priced hardware --albeit a really good selling point. They know tons of people pirate their software, but it means absolutely nothing without the hardware (you could argue that hackintosh's break this loop, but the number of people who use hackintosh's as main computers is fairly limited).

Microsoft employs serial numbers because they are primarily a software company, unlike Apple, who provides a closed all-in-one solution. When somebody pirates a copy of Windows, Microsoft loses 100% of that potential revenue. When somebody pirates OS X, Apple still has a previous hardware sale to fall back on, lessening the impact.

It also goes without saying that Apple uses us as a great, free marketing tool to tout its platform ("well, it is a bit expensive" - "but it's amazing and so easy to use!"), and as such, depends on us having the latest and greatest they have to offer. It makes sense that they would make it relatively easy to upgrade in order to introduce us to new features so that we can tell other potential Apple customers.