If an installation of theMountain Lion Developer Preview fails, try using Disk Utility from theRecovery HD to repair the disk. When installing on an NVDIA machine,moving windows or scrolling while in the install environment may causethe installer to crash.

This Mountain Lion Developer Preview isnot fully localized. Clipped text, untranslated UI, and functionalissues should be expected in languages other than English.

System Requirements
OS X Mountain Lion requires a Mac with a 64-bit kernel. Mountain Lion supports the following Mac models:
iMac (mid 2007 or later)
MacBook (13-inch Aluminum, 2008), (13-inch, Early 2009 or later)
MacBook Pro (13-inch, Mid-2009 or later), (15-inch, 2.4/2.2 GHz), (17-inch, Late 2007 or later)
MacBook Air (Late 2008 or later)
Mac Mini (Early 2009 or later)
Mac Pro (Early 2008 or later)
Xserve (Early 2009)

Known issues
32-bit kernel extensions are not supported in Mountain Lion
AirPlay mirroring is not supported with the with the current version of the Apple TV software
Game Center
The Game Center Server environment is set to Sandbox. Existing Sandbox accounts may be used, or you may create a new account
In the Sandbox environment:
Game & Friend Recommendations are not supported
Friends can view games in common but not friends other games
Photos are not supported
No email vetting and friend requests to un-vetted email addresses are allowed
No support for out of network friend requests is provided
Game matchmaking versioning restrictions are more relaxed
Some of the Game Detail information does not display (Game Provider, Pricing, etc.) in this Developer Preview
Search is not functional
No badges shown for Friend Requests
Peer-to-Peer GameKit API is not supported
Leaderboards, Achievements, or Players may be displayed incorrectly. To resolve this issue quit Game Center and re-launch

The new Notes application does not currently import the following types of notes:
Microsoft Exchange
Notes existing in sub-folders of IMAP accounts
Local notes in an On My Mac account
Notes in these accounts will be available in Mail
Notes shared via Messages may not include note content
Screen Sharing may not work between OS X Mountain Lion and Snow Leopard or earlier OS X releases in this Developer Preview
AppleScript is not fully functional in this Developer Preview
AppleScripts used to launch Applications which are not already open will time out
AppleScripts may not be able to send AppleEvents to Mail
DVD Player may not launch after inserting a DVD on some systems
DVD Movie Playback does not work on certain NVIDIA GPUs
Horizontalmetrics for Apple SD Gothic Neo are narrower than in AppleGothic.Applications localized to Korean may experience text layout underflow inmulti-line text strings
Video content with displays that use HDCP may experience graphics corruption on certain NVIDIA GPUs
Enabling display rotation causes kernel panic on certain NVIDIA GPUs
Signing into Setup Assistant with your AppleID does not sign you into iCloud
NSDocument-basedapplications which use auto-save & iCloud entitlements will beopted into the new Document Library automatically. The option to disablethis is not currently available
Kernel, kexts, and zones are nowbased at unpredictable addresses at each boot. The addresses in thekernel symbol table are unslid, and will not accurately reflect arunning system. Provided that Xcode 4.4 gdb is used, KASLR istransparent to kernel debugging
To temporarily disable KASLR, set slide=0 in the boot-args
Panics may occur when a Port Multiplier or PCI eSATA drive is attached
While booted into the Recovery Partition, you may be unable to connect to WiFi networks
Safari does not function in the Recovery Partition
Restoring from network backups in the Recovery Partition may fail

Bug Reporting

Thisbuild is being provided to you for testing and development purposes.Should you encounter any problems, please submit a bug report using theonline Bug Reporter at ;. Please make sure to include 10.8 (12A128p)in the bug title and description. This information will ensure that yourbug is processed quickly.

When submitting a bug report, pleasemake sure to include a Summary, Steps to Reproduce, Expected Results,Actual Results, and the diagnostic output generated by running ?sudosysdiagnose in the Terminal.

For complete instructions on submitting bug reports, please visit the Bug Reporting page at ;.

Thank you for your support.
Apple World Wide Developer Relations

Auto-Submission of Diagnostic and Usage Data

Bydefault, OS X Mountain Lion Developer Preview builds automatically sendanonymous diagnostic and usage data back to Apple. This includesinformation about crashes, freezes, kernel panics, and information abouthow you use Apple and third-party software, hardware, and services.This information is used to help Apple improve the quality andperformance of its products and services. If necessary, this setting canbe disabled in the Privacy tab in the Security & Privacy preferencepane.

Legal Notices

The software identified above isApple Confidential Information and your use of such software is subjectto the Apple Developer Connection Programs Terms and Conditions,including the Prototype License and Confidentiality Agreement attachedthereto. Distributing the software to anyone other than an ADC memberwho is working for the same entity as you is considered a violation ofyour agreement with Apple and is damaging to both Apple and those whodevelop for the Apple platform. We sincerely appreciate your efforts tokeep this software Confidential.

You agree that you will notexport or reexport any of the software or Confidential Informationreceived from Apple (a) into (or to a national or resident of) any U.S.embargoed countries (currently, Cuba, Iran, Libya, North Korea, Sudan,or Syria) without first obtaining proper authorization from the U.S.Government; or (b) to anyone on the U.S. Treasury Departments list ofSpecially Designated Nationals or the U.S. Department of Commerce DeniedPersons List or Entity List. You also agree that you will not use saidsoftware for any purposes where prohibited by United States law,including, without limitation, the development, design, manufacture orproduction of nuclear, missile, chemical or biological weapons.

ThisDeveloper Preview seed note is an appendix to the Prototype License andConfidentiality Agreement between Apple Computer, Inc. and theaddressee.

Download:

Mirror 1:

Mirror 2:

Mirror 3: