Mac OS X Public Beta – released in 2000
10 .0 — Cheetah; release date March 24, 2001
never really got out of beta, not recommended as a stable release of OS X; protected memory, preemptive multitasking; Mac OS X versions 10.0.1, 10.0.2, 10.0.3, and 10.0.4 all incorporated bug fixes and performance improvements. All versions of Mac OS X 10.0 require Mac OS 9.1 or later for Classic.
10.1 — Puma; release date September 29, 2001
1-CD installation, rainbow Apple menu (upper-left); considered the first working release of Mac OS X; although the code name of this product was Puma, it was not officially sold under this name; Versions 10.1.1, 10.1.2, 10.1.3, 10.1.4, an 10.1.5 all incorporated bug fixes
10.2 — Jaguar; August 13, 2002
2-CD installation, light-blue Apple logo in the Apple menu (upper-left), Finder windows and the menu bar were white with tiny horizontal grey lines to add texture. Overhaul of Mail, Sherlock searches multiple internet engines (but no longer searches your hard drive), spring loaded folders, Simple Finder, iChat, Bluetooth File exchange, Apple Midi Setup, iCal, iSync, Windows File Sharing and USB printer sharing, Rendezous, upgrades to Energy Saver allow for different energy settings with PowerBooks/iBooks, Airport base station software, Netboot, workgroup manager. Internet file sharing via WebDAV, support for Active Directory, IPv6, built-in software firewall; 10.2.1, 10.2.2, 10.2.3, 10.2.4, 10.2.5, and 10.2.6 incorporated bug fixes; Version 10.2.7 supported the new Power Macintosh G5, and 10.2.8 was released primarily to fix some security holes found in OpenSSH, but was pulled after a couple of days because a bug emerged that caused some Power Macintosh G4s to loose their network connections.
10.3 — Panther; released October 24, 2003
2-CD installation, requires 128 MB RAM, USB, 2 GB installation; the menu bar no longer had the horizontal grey lines for texture and windows had the brushed metal appearance; the left favorites sidebar in Finder windows, Expos, Fax software bundled within Print dialog box, Save as PDF, iChat AV (for video/audio conferencing), XCode
10.4 — Tiger; released April 29th, 2005
DVD Installation (4 CD installation optional with $10 trade-in program), requires built-in firewire; Finder windows change to smooth metal appearance; Spotlight, Dashboard Widgets, Automator RSS feeds in Safari, new version of Mail, Sync services.
10.5 (not yet released), codename Leopard — it was believed that 10.5 will be the operating system that will be ported to Intel-based processors, but on January 8th, 2006, the 10.4.4