Mac OS X¹ is an entirely new version of the Macintosh Operating System. It is based on a Berkeley Standard Distribution (BSD) core called Darwin, with a newly-developed Graphical User Interface (GUI) named Aqua on top.

OS X

There are some major differences between OS 9 and OS X.

Graphical User Interface

The GUI in OS X is referred to as the Aqua interface. Unix and Linux users tend to find it a breath of fresh air because it provides an interface which is arguably better than what any other window manager has been able to provide in the past. However, hard-core Mac users are divided about the system, as shown in this article.

One of the 'under-the-bonnet' oddities of OS X is the way that the GUI works. On a traditional UNIX-based OS² you would expect to find an X Server. This is not the case. However, it is possible to run X server on Mac OS X thanks to the distribution of XFree86, an implementation of the X Windows System, which is freely available for Darwin.

OS X retains the Finder (similar to the menu bar within a windows program), but has the addition of the Dock. The Dock is where minimized programs are held. It also contains quick-launch links to user-selected programs. It is comparable to the Windows Taskbar but it includes some nice additions - when a program is minimized the window contents appear in the dock and change in real time, which is handy if you want to wait for a webpage to load and write an email at the same time.

BSD

The decision to base OS X on a BSD core is very interesting. BSD was already available for PowerPC architecture - NetBSD is one example. Mac OS has always been an independent OS. This move pulled it closer to the PC. However it does have advantages - almost any application written for UNIX can be ported to Mac OS X whilst applications for OS 9 and below are supported through the Classic system. Darwin itself is also available for PC use.

The Classic Environment requires installation of Mac OS 9. When called upon, the environment simply loads OS 9 on top of OS X, allowing old applications to still operate. There is, of course, a slight reduction in performance, but for applications such as Word it is hardly noticeable.

Apple has offered little or no explanation as to why they've chosen to make this massive change. Their website does hint at a reason when it states 'We believe the open source model is the most effective form of development for certain types of software. By pooling expertise with the open source development community, we expect to improve the quality, performance and feature set of our software'. BSD has always been open source³ and Apple is keen to emphasize this point. It has been suggested that this was partly a matter of finance. By making software open source, bugs and security issues get resolved faster and by people who are working for free.

Later Versions

OS X 10.1

Version 10.1 was released in October 2001 after being delayed for several months. The upgrade included:

• A modification to the Dock enabling you to move it around the screen – it can now go down the right and left-hand side of the screen.

• A new minimize effect, which was already in 10.0, but hidden by Apple. On 10.0, it is accessible by using a program such as TinkerTool.

• The ability to put Docklings into the menu bar. A Dockling is an application that gives visual feedback from the Dock. This is comparable to the System Tray on Windows⁴. For some unknown reason Apple has advised developers to avoid developing Docklings.

• A more organised System Preferences panel. Each preference has been categorized.

• Filenames are rendered in full rather than being truncated. OS X can also be set to hide filename extensions⁵.

• Applications launch at twice the speed. While this claim may not be true, there is a noticeable increase in speed.

• They have also improved the OS' networking features and AppleScripted more core applications and utilities.

OS X 10.1.1

According to Apple:

10.1.1 delivers improvements for many USB and FireWire devices, including support for additional digital cameras, and overall improvements to CD and DVD Burning. The update includes enhancements to AFP, SMB and WebDAV networking, updates to the Finder and Mail applications, as well as improved support for printing. In addition, hardware accelerated video mirroring has been enabled for the new PowerBook G4.

OS X 10.2

The release of this update has been delayed until summer 2002. This is because of concerns raised that updates are being released too quickly. Apple has promised that they will make essential updates available as 10.1.x