Apple is planning to release a publicly available beta of the upcoming OS X Yosemite later this month, according to sources briefed on the plans. This release will mark the first time Apple has released a public beta of a new OS X version in over a decade.

Apple released a Developer Preview of Yosemite following the software’s announcement at the June Worldwide Developers Conference, and the company has continued to release updates every two to three weeks since that time. Apple previously said that it will release a public beta of Yosemite this summer…

Apple is also planning to release the fourth preview for registered developers later today, the sources said. Of course, these plans are fluid and the release could be pushed back to a later date. It is possible that a new iOS 8 beta will also arrive today for developers. (Update: Yosemite Preview 4 and iOS 8 beta 4 have each been released).

Apple has chosen to wait until later this month to release the public beta in order to ensure that the operating system is polished enough to be used by consumers, according to the sources. Because of the sometimes uncertain nature of software development, the release of the beta could be pushed back to early next month, the sources added.

Apple has said that it plans to release the final version of Yosemite this fall, which will include significant user-interface changes that are akin to iOS’s refreshed look, improved Spotlight searching, enhanced Messages, Safari, and Mail applications, and new Continuity and Handoff features to more seamlessly integrate with iPhones and iPads.