Mac OS X Tiger
Mac OS X 10.4 "Tiger" is a version of Mac OS X. After several successful desktop releases, and the establishment of Mac OS X as a serious desktop operating system with Jaguar and Panther, Apple pushed forward yet again with the next large update of OS X - 10.4 "Tiger". On June 28, 2004 Tiger was announced at the WWDC, and took one of the longest wait times, second to 10.5 "Leopard", to release on April 29, 2005. Outside of the introduction of Exposé in Panther (the previous release), Tiger added several notable killer features that would become OS X icons throughout the decade, and was notable for being the longest running OS X release in history with 11 minor updates (10.4.11), while all other versions of OS X at most had received 8 or 9 updates in total.
One of the first breakthrough features was dubbed "Spotlight", which improved upon the per-application instant search stack and APIs introduced in 10.3 "Panther" was a new system-wide expansion of this technology that was now available to all applications, including to major OS X applications such as System Preferences and Address Book with full metadata details and "smart folders", a new saved search feature in the Finder, Mail 2, and iTunes. Spotlight was prominently featured throughout the entire OS, from the installation welcome window and introduction video, to the highlighting effect used when searching with the new toolbar in System Preferences. The Menubar also gained a blue (or graphite, depending on Appearance preferences) circle with the Spotlight search glass inside, which allowed universal searching of the entire system, whether files, folders, e-mails, or any other data specified in Spotlight preferences. Spotlight was developed much faster than competing desktop environment search engines at the time, and indexed new drives and ran as a system service in the background by default. This feature was so successful that it is widely speculated today that the Aero Search and Start Search features in Windows Vista may have at least been heavily influenced in design and placement by Spotlight.
Tiger also brought a new Grapher application (not seen since Graphing Calculator on Mac OS 9), and a new Dictionary application with a system-wide dictionary and thesaurus that could be called by applications as a service, such as in TextEdit. It also introduced RSS to Safari, and a new layered widget system called Dashboard to OS X, which was added as F12 by default, next to the F9-F11 Exposé key set previously assigned in Panther (although the MacBook had a dedicated Dashboard key and moved it). Tiger also brought several important security enhancements to Safari, and a redesigned firewall with Stealth Mode and other controls for easier management. New to Mac OS X was also the H.264 codec, which allowed editing and viewing of videos packaged in a more compact encoding along with QuickTime 7, which was later backported to Panther users. Tiger also brought several Accessibility improvements, including a redesigned Accessibility preference and Speech pane, and a new system-wide screen reading feature called VoiceOver. Parental Controls were also first added to Tiger for easier household management, although Leopard would greatly enhance this feature. Apple also focused on improving the Mac experience in the home and work with Tiger as well. Integrated into Setup Assistant and also as a seperate app, Migration Assistant allowed Mac users to retrieve and sync data, and additional support for the .Mac and iTools services (the predecessor to iCloud) with better syncing were added, along with a new automated scripting framework and the Automator application.
As with Panther, Apple continued to carefully craft the young Aqua into a more refined and mature UI, continuing the use of brushed metal over plastics, a gloss/glass menubar style that mirrored the current product lineup, and changed the overall look of highlights and the Apple logo. Aqua now allowed cycling through windows from the Window menu in addition to Exposé, and brought a new aluminum unified title and toolbar style in select applications, such as System Preferences and Mail, that would finally be completed and used system-wide in all applications in the next release, 10.5 Leopard.
In pursuit of 64-bit computing, Mac OS X 10.4 continued this evolution by allowing 64-bit application support on the system by allowing applications designed for the new framework to address more than 4 GB of memory on supported systems, such as the G5, and also allowed 64-bit Macs to boot from the unified Tiger DVD, whereas 10.3 required a machine/CPU-specific copy for the G5. Despite the improvements, 64-bit support was far from complete, and many more improvements would follow in 10.5, and full 64-bit support would finally be complete from the kernel and system extensions down to the userland with the release of 10.6 in August 2009. 10.4 also improved SMP and changed the OS X boot process and significantly improved system launch, boot, and response times by using the new launchd process to spawn different jobs on the system, and made significant improvements for filesystem support, including for mounting NTFS drives. Minor improvements were made to the updated Finder and to the new Finder Labels previously introduced in 10.3 Panther to address their behavior, and tools within the BSD subsystem, such as the cp command, were patched and released with Tiger to better handle resource forks better than previous releases had. The development environment, XCode, also received significant improvements, such as the ability to visually model and use graphics with CoreImage and CoreVideo. Quartz Composer, Core Data, and several new APIs that extended on the previous work done in Panther were also added to 10.4 Tiger for developers as well. Finally, Tiger also introduced AU Lab and crisper audio playback and support in Mac OS X.
With the release of 10.4.4, Tiger finally supported the new Intel (x86) based Core Solo and Core Duo Mac models that were part of Apple's transition from the PowerPC architecture to the Intel architecture that started in 2006. Some Intel models required later revisions such as 10.4.7; it could very well be that due to the transition, Tiger remained the longest running OS X version in history. The change also prompted the Hackintosh community to rise in popularity with installation guides and support for running Mac OS X on x86-based computers as a 'hack', hence the title. This movement was criticized by Apple, with several kernel and system patches made to prevent it with most later major software updates to Tiger, and is considered to break the SLA -- as OS X is not running on "Apple-branded" hardware. Regardless, Tiger still required architecture-specific discs and it wouldn't be until 10.5 Leopard that Apple would finally release OS X for a quad-architecture universally on one disc.
Overall, Mac OS X Tiger clearly helped evolve Mac OS X into an advanced operating system, which helped to set both performance and feature set expectations in later releases. Mac OS X 10.4.11 is the last version to support G3 processors and early G4 processors (though rare, early developer builds of Leopard can legitimately boot on G3, and all G4 processors can run Leopard with a CPU clock speed OpenFirmware hack.)