Mac OS X Leopard
Mac OS X Leopard (version 10.5) is the sixth major release of Apple's Mac OS X operating system, introduced as a comprehensive update featuring over 300 enhancements to improve user productivity, file management, and system performance.[1] Released on October 26, 2007, it marked the final version of Mac OS X to support both Intel and PowerPC processors, bridging Apple's transition to Intel-based hardware while delivering groundbreaking tools like Time Machine for automated backups and easy file restoration.[2][3] Priced at $129 for a single-user license and $199 for a five-user Family Pack, Leopard was available through Apple retail stores, the online Apple Store, and authorized resellers, with upgrade options for recent Mac purchasers.[2] Leopard's interface innovations transformed the desktop experience, starting with a redesigned Dock that incorporated Stacks—organizable folders for quick access to downloads, documents, and applications—reducing clutter and enhancing navigation.[1] The Finder received significant updates, including Cover Flow for visual browsing of files and photos, and Quick Look for instant previews of documents, images, and media without opening full applications.[1] Spaces, a virtual desktop manager, allowed users to create and switch between multiple workspaces tailored to specific tasks, such as work or entertainment, promoting efficient multitasking.[4] Additionally, full native 64-bit support enabled applications to leverage advanced processing power, while optimizations for multi-core processors improved overall system responsiveness.[4] Beyond core desktop features, Leopard enhanced built-in applications for communication and media. Mail added RSS feed integration, customizable stationery templates, smart mailboxes, and To Do lists for better email organization.[4] iChat introduced video effects, screen sharing, and presentation modes like iChat Theater, facilitating richer remote interactions.[4] System requirements were modest for the era, needing a Mac with an Intel, PowerPC G5, or PowerPC G4 (867 MHz or faster) processor, 512 MB of RAM, 9 GB of available disk space, and a DVD drive for installation, ensuring broad compatibility across Apple's hardware lineup.[3] These advancements positioned Leopard as a pivotal release, solidifying Mac OS X's reputation for intuitive design and innovative functionality.[1]Development and Announcement
Background and Development Process
Development of Mac OS X Leopard, internally designated as version 10.5, began shortly after the release of Mac OS X Tiger (version 10.4) in 2005. The project was led by Scott Forstall, who assumed responsibility for Mac OS X development in 2006 after serving as vice president of platform experience.[5] The effort emphasized building upon Tiger's foundation by enhancing system stability and expanding features, while addressing the ongoing transition from PowerPC to Intel processors through extended support for universal binaries that allowed seamless execution on both architectures.[6][4] Key technical decisions during development included implementing 64-bit support for applications and graphics while retaining a 32-bit kernel to ensure broad compatibility with existing 32-bit software and drivers. This hybrid approach enabled Leopard to run 64-bit applications alongside legacy 32-bit ones without requiring immediate hardware upgrades. Additionally, Apple pursued and achieved UNIX 03 certification for the Intel-based version, positioning Leopard as a standards-compliant UNIX system to appeal to enterprise users and developers seeking portability.[7][8][9] Beta testing commenced with the first developer preview unveiled at Apple's Worldwide Developers Conference (WWDC) in August 2006, where attendees received early builds demonstrating core enhancements. A more advanced, near-final developer beta was released in June 2007 at WWDC, allowing broader testing among registered developers to refine stability and performance ahead of the general release on October 26, 2007.[4][1]Public Announcement and Marketing
Mac OS X Leopard was first publicly announced at Apple's Worldwide Developers Conference (WWDC) in June 2005, where CEO Steve Jobs positioned it as the next major release following Mac OS X Tiger (version 10.4), with an initial target ship date by the end of 2006.[10] Due to development delays, including earlier adjustments related to the Intel processor transition and a further postponement in April 2007 due to the diversion of engineering resources to the iPhone project, Apple provided an initial preview at WWDC 2006 and unveiled a near-final version at WWDC 2007, where Jobs demonstrated key features and noted the inclusion of over 300 enhancements.[11][1] Apple's marketing campaign framed Leopard as a transformative upgrade that extended the life of existing hardware, akin to "adding a new Mac to your Mac," while stressing its innovations in user interface and performance.[12] The promotion relied heavily on keynote presentations, such as the WWDC 2007 demo of Time Machine—a revolutionary backup tool—and targeted advertisements that showcased ease of use, visual effects like Stacks in the Dock, and seamless integration with Intel-based systems.[13] Pre-orders for Leopard began in July 2007 through select retailers like Amazon, ahead of the official launch, with Apple's online store opening orders on October 16, 2007.[14] The software was priced at $129 for a single-user upgrade license and $199 for the Family Pack, which supported up to five users in one household.[2] To highlight Leopard's universal binary architecture, which ensured compatibility across PowerPC and Intel processors, Apple coordinated announcements with hardware refreshes; for instance, the redesigned aluminum iMacs introduced at the August 7, 2007 special event, which were optimized for the latest Intel chips and eligible for a free upgrade to Leopard upon its release, demonstrating its compatibility and performance.[15] Updated MacBook models, refreshed earlier in 2007, were similarly marketed to emphasize the OS's role in the smooth Intel transition.[16]Release and Distribution
Official Release Timeline
Mac OS X Leopard, version 10.5, was initially released to the public on October 26, 2007, with build number 9A581. This retail launch marked the sixth major version of Apple's operating system for Macintosh computers, available through Apple retail stores and authorized resellers starting at 6:00 p.m. local time.[17] The Mac OS X Server edition, version 10.5, was released simultaneously with the client version on the same date, October 26, 2007, to support enterprise and server environments.[18] Apple issued several major updates to Leopard throughout its lifecycle, focusing on stability, compatibility, and security enhancements. The following table summarizes the key update releases:| Version | Release Date | Build Number | Notes |
|---|---|---|---|
| 10.5.1 | November 15, 2007 | 9B18 | General bug fixes and security improvements.[19][20] |
| 10.5.2 | February 11, 2008 | 9C31 | Included adjustable transparency features and further stability updates.[21][20] |
| 10.5.8 | August 13, 2009 | 9L31a | Final major update with comprehensive security patches.[22][23] |