For the first time in more than a decade, Apple's allowing any Mac user to test the latest version of OS X before its full release. Starting on Thursday, a public beta program will allow one million people to sign up to try all the new features in 10.10 Yosemite, from Safari and Spotlight to the vast, aggressive levels of translucency. This is a big shift for Apple, which has taken a number of steps toward working more in public: Apple will be updating the beta frequently (though not as often as it pushes new features to developers), giving users a window into the development process.
Yosemite won't be out officially until the fall, and Apple is careful to note that the new OS isn't finished yet. But if you're itching to see how much better Mac notifications and group chats are about to get, today's your chance. As with any beta, of course, you should proceed with caution. If you're going to install Yosemite, there are a couple of tips and cautionary measures Apple recommends:
Sadly, a few of Yosemite's best features — its integration with iOS 8 in particular — won't be available in the beta, and there's no equivalent beta for iPhone and iPad users. But this is a rare peek into the future from Apple, and from what we've seen of Yosemite, there's a lot to be excited for.