If you're a developer already using the Golden Master release of Mavericks, you won't notice it either from the Mac App Store or the Software Update mechanism, but Apple appears to have replaced the GM build with a new version. The build number has changed, according to 9to5Mac.
Without a way to update the previous GM build to the new release, some users have reinstalled a fresh copy to get the update, according to the report. It's unclear what the differences are.
Mavericks went GM earlier this month, and Apple petitioned registered Mac developers last week to submit apps for approval for distribution through the Mac App Store - something they typically do imminently before the release of a new operating system.
Apple has scheduled an event for Tuesday, October 22, 2013, where they're expected to introduce new hardware and offer a release date for Mavericks.
Looking forward to Mavericks? What are your favorite features? To remind yourself of what's changing in Mavericks, take a look at our preview.