Developer Preview 6 appeared in the Mac App Store for registered developers overnight. 9to5Mac.com first reported its arrival.
Today’s update followed by two weeks the fifth version of the preview; that had been released two weeks after the fourth, which debuted 21 July.
Although Apple has also handed non-developers a public beta, the Cupertino-based company has said it plans to update that edition less frequently. Apple released the first public beta on 24 July.
If Apple ships a new public beta after every other developer preview, as some expect, then it would offer users monthly updates: Thus the next public beta could release on Thursday, 21 August.
Both the developer previews and the public beta can be installed only on Macs running OS X Mavericks, the October 2012 upgrade. Yosemite will run on iMacs from the mid-2007 model on; 13in MacBooks from late 2008 (aluminium case) and early 2009 (plastic case) forward; MacBook Pro notebooks from mid- and late-2007 and on; MacBook Air laptops from late 2008 and later; Mac mini desktops from early 2009 and after; and the much beefier Mac Pro from early 2008 and later.
Participants in the Yosemite beta will be able to install the final edition in place of the sneak peek when the polished version launches this spring.
If Apple hews to a once-every-four-weeks schedule for the public beta, and offers an update Thursday, it will have an opportunity to issue just two more before the projected 22 October release date.