Platform: Mac; Apple announcement
Introduction and announcement; not a sales date.
Apple source ↗Apple unveiled Mac OS X 10.6 Snow Leopard on June 8, 2009, targeting September. On August 24 it brought announced availability forward to August 28 and opened preorders. The US$29 price was a Leopard upgrade; the Family Pack was $49. For Tiger users with Intel Macs, Apple offered the $169 Mac Box Set with iLife '09 and iWork '09. These were not equivalent products at one price.

Apple · Snow Leopard · 2009-06-08 · Apple · Snow Leopard · 2009-08-24
Snow Leopard brought Finder, Mail, iCal, iChat and Safari to 64-bit while retaining 32-bit application compatibility. Grand Central Dispatch gave developers tools for multicore processors, while OpenCL let them use GPUs for non-graphics calculations. QuickTime X redesigned the player; Mail, Address Book and iCal supported Exchange Server 2007.
Apple · Snow Leopard · 2009-06-08 · Apple · Snow Leopard · 2009-08-24
Announced requirements were an Intel processor and at least 1 GB RAM. Running Leopard was not enough: this transition excluded PowerPC. Speed and free-space figures in the releases came from particular Apple tests, not universal guarantees; this entry does not turn them into results for every machine.
Apple · Snow Leopard · 2009-06-08 · Apple · Snow Leopard · 2009-08-24
The Mac App Store did not originate with Lion: Apple announced its opening on January 6, 2011 as part of 10.6.6 through Software Update. The table adds 10.6.8, recorded by Apple on June 23, 2011. The initial system is separated from features arriving in later revisions, without claiming every subversion or build.
Apple · Mac App Store / 10.6.6 · 2011-01-06 · Apple · 2011-2012
Selected releases, not a complete history. Dates follow Apple's release records, not the latest page edit. No builds are included.
ISO date: year-month-day.
Platform: Mac; Apple announcement
Introduction and announcement; not a sales date.
Apple source ↗Platform: Mac; Apple announcement
Announced availability; this release does not establish actual sales.
Apple source ↗Platform: Mac OS X client
Mac App Store opens through 10.6.6; not a feature of the initial 2009 system.
Apple source ↗Platform: Mac OS X client
Release date recorded by Apple; client update.
Apple source ↗