Apple has announced the release of their OS X Beta Seed Program today, which allows anyone with an Apple ID and a Mac to download and run the latest developer build of Mac OS X 10.9.3—the most updated beta version of Mavericks.
The OS X Beta Seed Program allows us to run software that was once only available to limited test audiences or registered Apple developers—with the latter costing $99 a year for a membership. With this program, not only do we get our hands on extremely new software, but we also provide help and feedback to Apple in order to make the OS X experience better for all.
If you're interested in testing out the latest beta version of OS X Mavericks, head over to the OS X Beta Seed Program, log in with your Apple credentials, make a backup of your device, download the software, and update your computer.
Once your computer reboots, you'll have the latest developer version of OS X, ready for tinkering and bug reports to Apple.