Now that you've digested everything that's new in OS X Yosemite, you're probably itching to try it out for yourself. The good news is that Apple's happy for you to do so: for the first time since Cheetah in 2000, non-developers have the opportunity to give an upcoming operating system a test run. For free.
You must be in one of the first million people to sign up though, so don't delay. Here's what you need to do, and what happens next.
Signing up for the OS X Beta Program
"Help shape OS X Yosemite. Sign up for our Beta Program," announces the official sign-up page on Apple's website. Click the Sign up button, enter your Apple ID and password, accept the program agreement, and you're good to go, no payment necessary.
You'll receive an email notification when the software is ready to download and install. Apple hasn't said when this will be, but with a public release date in the fall a good bet for a beta version would be any time over the summer. The opportunity to try out Yosemite is part of a larger public beta testing initiative Apple launched in April.
The usual caveats for testing beta software apply here. Mostly, it's going to have lots and lots of bugs. Apple recommends making a backup of all your data before you install the OS, and warns against using it on "business-critical" systems until all of the wrinkles have been ironed out. Many of your existing apps and devices may not be fully compatible right now.
If you're signed up for the Mac Developer Program—which will set you back $99 a year — you can get your hands on an early version of Yosemite today. It's a steep price to pay for a head start of just a few weeks (and technically speaking you should be a genuine developer) but you might consider it worth it if you're thinking of getting into desktop app development anyway, as there are many other perks.
What to remember
Sign up for the Mac OS X Beta Program and you're promising not to blow the lid on features and functionality coming down the line, so avoid sharing screenshots and other software information. "Don't blog, post screenshots, tweet or publicly post information about the pre-release Apple software," says the official FAQ page.
Apple wants something out of this too, in the form of user feedback. You should report any bugs or strange behavior you come across through the Feedback Assistant app, which appears prominently in the pre-release software.
Note too that not all of the features Apple announced for Yosemite this week will be in the beta code. You'll have to wait for the full release for Handoff, Instant Hotspot and iCloud Documents, for example, while Spotlight suggestions will only be available to users in the US.
Other than that, you should be all set to strike out on the cuttingest—and buggiest—of OS X edges. Have fun, and be safe out there.