Printing is not the most sexy of tasks, but Apple has paid a great deal of attention to printing in Leopard. Understandably, most of the new printing features have gone unnoticed by the mainstream press, overshadowed by Time Machine, Quick Look and Spaces.

The Common UNIX Printing System (CUPS)
The open source CUPS project was introduced as the underlying printing system in Mac OS X 10.2 (Jaguar). In a slightly surprising move, Apple acquired the open source CUPS project and hired its main developer, Michael Sweet, in February of this year.

No surprise, then, that CUPS in Leopard has been brought bang up-to-date, moving from version 1.1 in Tiger to version 1.3. The increase in version brings a range of new features, including:

• An overhauled web interface (found at localhost:631), which adds printer searching, many admin options and more-consistent interface
• Support for launchd — cupsd is now launched on demand
• Thread-safety — in-keeping with Apple’s focus on multicore optimisations, the entire CUPS API is now thread-safe
• IPv6 support
• 16-bit per channel colour on supported devices
• Greater support for IPP, including IPP notifications
• Printer sharing via LDAP v3, optionally with SSL (I’m not sure if this is exposed in System Preferences, but it’s definitely there under-the-hood)
• Greatly improved security and authentication, including Kerberos authentication, complete support for the Mac OS X Authorization Services framework and awareness of POSIX ACLs
• Command line configuration from the new cupsctl command

And this list barely scratches the surface – printing in Leopard really is massively improved.

New print dialogs
This was mentioned in MacWorld’s ten overlooked Leopard gems and rightly so; Leopard finally brings navigable print-previews and page orientation settings to the print dialog box:

Miscellany
Leopard also adds “Location-Aware Printing”, which will automatically set the default printer based, presumably, on the currently available network. And finally, Apple will be distributing third-party printer drivers through Software Update from Leopard onwards.

Some critics have (in my opinion, inaccurately) commented that Leopard focusses too much on eye-candy and visual superfluities. That clearly isn’t the case with printing, which has seen massive under-the-hood improvements in addition to some highly functional improvements to the user interface.