The free update is available via the Mac App Store, with delta (540.46 MB - from 10.8.2) and combo (793.69 MB - from any version of 10.8) updaters now ready for download from the Apple Support Downloads site.
With OS X Mountain Lion 10.8.3 Update and the included Safari 6.0.3, Apple has squashed numerous nagging bugs, many of which were extremely specific and were thus overlooked in the larger 10.8.2 release from nearly six months ago (see “ OS X 10.8.2 Eases Notification Center, Messages Frustrations,” 19 September 2012).
#1578: Apple delays CSAM detection, upgrade Quicken 2007 to Quicken Deluxe, App Store settlement and regulatory changes.Apple lawsuit decided, Internet privacy limitations, combine Mac speakers #1579: Apple “California Streaming” event, OS security updates, Epic Games v.#1580: iPhone 13 and iPhone 13 Pro, Apple Watch Series 7, redesigned iPad mini, and upgraded iPad, plus iOS 15, iPadOS 15, watchOS 8, and tvOS 15.
smart displays, iOS 12.5.5 and Catalina security update, iPhone 13 problem with Apple Watch unlocking