Release record
Mountain Lion
Release notes
Editorial synthesis with inline references and a source ledger when citations are available.
OS X Mountain Lion 10.8 became available from the Mac App Store on July 25, 2012. Its documented launch package centered on iCloud continuity, Messages, Notification Center, system sharing, Dictation, AirPlay, Game Center, Gatekeeper, Power Nap, Safari, regional services, and a lower-cost digital upgrade path.[1][2]
Apple issued a developer preview on February 16 and described a late-summer target, then announced in June that Mountain Lion would arrive in July. The July 25 announcement is the controlling source for the actual public date and shipped feature set.[3][4][5]
At launch, iCloud could configure supported built-in apps and synchronize eligible information and iWork documents. Messages extended iMessage to the Mac, while Notification Center and the common sharing layer reorganized how apps surfaced alerts and sent content.[6][7]
Dictation worked in compatible text fields, AirPlay supported display mirroring and audio output, Game Center connected compatible multiplayer games across Apple devices, and the release added Chinese input, dictionary, account, search, microblogging, and video-sharing integrations.[8]
On July 30, Apple reported more than three million Mountain Lion downloads in the first four days. That figure is retained as an attributed vendor report rather than an independently audited adoption estimate.[9]
Structured changes require explicit support from Apple's July 25 public-launch announcement. Earlier materials are used only for development context, for a detail attached to a launch-confirmed feature, or to document a superseded claim. Facebook integration is excluded because Apple said it would arrive in a later software update; preview-only developer APIs are also excluded.[10][11][12]
Gatekeeper is recorded as a confirmed launch security feature, but no launch CVE repair set is inferred. Apple's archived 2011–2012 security index does not list Mountain Lion 10.8 as a July 25 security release and instead begins retained Mountain Lion update coverage with 10.8.2 on September 19.[13][14]
Source ledger
Sources are linked to the claims they support. Publication and access dates are shown when available.
Apple Newsroom · Apple · 2012-07-25T00:00:00.000Z · July 25, 2012; overview through Pricing & Availability
Apple Newsroom · Apple · 2012-07-30T00:00:00.000Z · July 30 availability and feature confirmation
Apple Newsroom · Apple · 2012-02-16T00:00:00.000Z · February 16 developer-preview availability
Apple Newsroom · Apple · 2012-07-25T00:00:00.000Z · July 25 public availability
Apple Newsroom · Apple · 2012-06-11T00:00:00.000Z · June 11 planned July availability
Apple Newsroom · Apple · 2012-07-25T00:00:00.000Z · Feature list; iCloud through system-wide Sharing
Apple Newsroom · Apple · 2012-07-30T00:00:00.000Z · July 30 feature confirmation
Apple Newsroom · Apple · 2012-07-25T00:00:00.000Z · Feature list; Dictation through features for China
Apple Newsroom · Apple · 2012-07-30T00:00:00.000Z · July 30 download report
Apple Newsroom · Apple · 2012-02-16T00:00:00.000Z · Developer-preview feature and API sections
Apple Newsroom · Apple · 2012-06-11T00:00:00.000Z · Pre-release feature details; Facebook footnote
Apple Newsroom · Apple · 2012-07-25T00:00:00.000Z · Public feature list; Facebook footnote
Apple Support · Apple · 2023-08-10T00:00:00.000Z · 2012 security-release table; Safari 6.0 and Mountain Lion 10.8.2 entries
Apple Newsroom · Apple · 2012-07-25T00:00:00.000Z · Additional features; Gatekeeper
Apple Support · Apple · 2023-08-10T00:00:00.000Z · 2012 security-release chronology
Apple Newsroom · Apple · 2012-02-16T00:00:00.000Z · February 16 developer preview
Apple Newsroom · Apple · 2012-07-30T00:00:00.000Z · July 30 post-launch confirmation
Apple Newsroom · Apple · 2012-06-11T00:00:00.000Z · June 11 pre-release announcement
Documented & observed
Source-linked features, fixes, known issues, removals, and community-observed behavior recorded across this version’s appearances and verified builds.
Release changes
Features, fixes, removals, and regressions first observed in this release record.
enhancement · changed
Apple's public announcement characterized the bundled browser as faster. The entry preserves that as a vendor-authored launch claim and does not present it as an independent benchmark result.
Recorded at Public
feature · introduced
The system-wide sharing model included regional microblogging and video destinations for Chinese users.
Recorded at Public
feature · introduced
Mac users gained an iMessage client for communicating with supported Macs, iPhones, iPads, and iPod touch devices, replacing iChat as the primary built-in messaging app.
Recorded at Public
compatibility · changed
Apple used the Mac App Store as the public delivery path and allowed eligible installations to move directly from either of the two preceding OS X generations.
Recorded at Public
compatibility · changed
The public launch defined minimum software, memory, and free-space requirements; model-specific feature support could still vary beyond those baseline conditions.
Recorded at Public
feature · introduced
The release added a low-interruption background-update mode for supported Mac hardware; the public record does not imply that every Mountain Lion-compatible Mac supported it.
Recorded at Public
feature · introduced
Mountain Lion added a consolidated notification surface for Mail, Calendar, Messages, Reminders, system updates, and compatible third-party software.
Recorded at Public
enhancement · changed
The release brought several built-in communication and productivity apps into one iCloud-oriented setup flow instead of treating each service as a separate account experience.
Recorded at Public
enhancement · changed
The system reduced account-configuration friction for supported regional mail services and exposed a major Chinese search provider inside Safari.
Recorded at Public
enhancement · changed
Eligible documents, notes, reminders, and other supported information could remain synchronized so work begun on a Mac or mobile Apple device could continue elsewhere.
Recorded at Public
enhancement · changed
The release expanded built-in language support for Chinese users through revised text entry and a dedicated reference dictionary.
Recorded at Public
feature · introduced
The public release extended its AirPlay support beyond display mirroring to compatible audio playback equipment.
Recorded at Public
security · introduced
Mountain Lion introduced a trust-policy layer for downloaded Mac applications. The structured claim stays at the mechanism confirmed by Apple's public-launch announcement and does not infer a launch CVE repair set.
Recorded at Public
feature · introduced
Mountain Lion added wireless display mirroring to compatible Apple TV hardware, with Apple's final launch material raising the stated ceiling from the developer preview's 720p description to up to 1080p.
Recorded at Public
feature · introduced
Apps could expose a shared system action for sending supported content without forcing users to switch to a separate app, with single sign-in support for named third-party services.
Recorded at Public
feature · introduced
The Mac joined Apple's social gaming network, allowing compatible games to connect players across Mac, iPhone, iPad, and iPod touch.
Recorded at Public
feature · introduced
The release made speech-to-text input available as a system capability rather than limiting it to one built-in application.
Recorded at Public
Milestones
Every recorded channel appearance in chronological order. Open an appearance for any available build, scope, notes, and sources.
Developer beta
Public release
OS X Mountain Lion 10.8 reached the public channel on July 25, 2012 with cross-device services, communication, notifications, sharing, media, input, security, regional, delivery, and compatibility changes.
Historical context
Pace, intervals, and duration compared with earlier releases on the same platform.
Cycle vs. platform average
160d (avg: 101d)
59 days longer than the macOS average
Longest gap in this cycle
160 days
Between Beta 1 and Public