updated 12:05 am EDT, Sun October 26, 2008
New Snow Leopard build
Apple's second build of Snow Leopard, which was released to developers earlier this weekend, brings a number of changes to the next version of the Mac OS X operating system, including a new "simplified" installation experience, preliminary support for HFS+ file system compression and 64-bit kernel, a rewritten Cocoa-based Finder for performance improvements, a new default gamma setting for viewing colors, and basic reading and editing support for Microsoft Exchange in Mail, iCal and Address Book. Apple also noted other multi-core enhancements and low-level kernel operating system changes, including those to queue management in Grand Central its technology for enabling developers to better leverage multi-core processors. The pre-release software, offered to developers for testing, is the second version made available, following the initial preview release at WWDC in June; the final version of operating system, designed for Intel-based Macs only, is expected to ship as Mac OS X 10.6 next year.
Apple's Snow Leopard is expected to take the 64-bit support introduced Leopard to the next level. The latest build enables 64-bit kernel support on some Macs and enables both audio and AirPort support for testing purposes -- specifically that early 2008 models of the Mac Pro, 15-inch and 17-inch MacBook Pro and Xserve can be used for 64-bit kernel development. Apple noted that in SnowLeopard, the 64-bit kernel will be used by default on the Xserve and the Mac Pro and MacBook Pro systems (developers were given both startup key options and terminal commands for booting into the 64-bit kernel). Apple also offered the necessary support for porting kexts (dynamically loaded extensions that provide additional OS or kernel functions) to 64-bit and "strongly encouraged" developers to begin the transition.
The release notes cautioned, however, that some 64-bit features were still in development and that Shark, Apple's performance testing tool for developers, does not work with the new 64-bit kernel and that both sleep / wake and power management and graphics acceleration is not yet supported.
HFS+ file compression
Although not as high-profile as the ZFS support expected in Snow Leopard, Apple noted that it has continued to build on the HFS+ file format, saying that new file compression has been added to the HFS+ file system. Apple said that the compression was designed to be used with Apple System and Application files that are normally read-only/updatable.
Apple emphasized that it is not a new file system, but that developers who write disk utility programs would need to recognize these files exist and some details about how they are implemented. The compressed files would be supported on both Tiger and Leopard systems, but would show up as files of zero size and have the indicated extended attributes.
"These files are not normally copied by users, however, if they are, the copies will be expanded to their normal size," Apple noted in the release notes. "This is not a new file system format and does not require volumes to be repartitioned."
Confirming earlier reports, Apple says the latest Snow Leopard build has made "much progress" in transition of the Finder from a legacy Carbon application to Cocoa. The transition, expected to be completed in time for the release of Snow Leopard, includes all user-facing applications in Mac OS X and has Apple has completed much of the transition with the exception of a select few application, it said in the notes.
Default Gamma setting changed
Apple also said that it has changed the default gamma display setting to help both consumers and professionals. The Cupertino-based company made adjusted the default settings to be closer to those used by Windows PCs and televisions. According to the latest Snow Leopard release notes, the default gamma setting has been changed from 1.8 to 2.2 -- which is recommended by many professionals -- and that applications that override the deftault and assume a gamma 1.8 setting may have different onscreen and printed output than they did in previous releases of Mac OS X. Although the 1.8 setting has been used as the default by Apple since its earliest monitors and laser printers, Apple already actually recommends on its website to re-calibrate monitors to the 2.2 setting for photographic work.
Enhanced Exchange support
Specifically, Apple said that Snow Leopard now contains additional support for Microsoft Exchange 2007 via Mail, iCal and Address Book, including support for basic browsing as well as creation and editing of Microsoft Exchange data. The company, however, said that "much functionality and polish is still forthcoming which may impede full Exchange use in this seed."
The company, however, urged developers to test a variety features, including a new auto-discovery feature in Apple's Mail.app application designed to streamline the configuration process and simultaneously configure both Address Book and iCal. For servers that do not support auto-configuration, users can select "Microsoft Exchange 2007″ as a new account to type and manually enter server settings. The new Exchange support allows reading and writing of Messages, Notes, and To Do's as well as scheduling events and checking recipient and room availability within iCal, Apple's free calendaring application and adding contacts and groups within "Address Book" (version 5.0) -- although it appears that Apple has also bundled the older Leopard version of application as "Address Book (Leopard)" for legacy support.
Working with the build, Apple told developers about several Exchange limitations, including noting that working offline mode in Mail.app is not yet supported and that event invitations, delegation authorizations; some other types of messages are not currently displayed and conversion of messages moved between Exchange and other accounts was still buggy; that undo is not fully supported within Mail; that creating calendars on Microsoft Exchange accounts is not yet supported in iCal.
Finally, Apple also noted that split view support has been added to Terminal, tab support has been enhanced with a contextual menu and that it has added the ability to create new tabs by double clicking. In addition, Snow Leopard uses Java SE 6, released for Leopard systems in September, for all Java applications and applets.