Smith Micro has included Leopard integration features in StuffIt Deluxe 2009 for Mac OS X, a new version of the cross-platform file compression, encoding, encryption, and backup utility. StuffIt Deluxe 2009 can expand over 30 compression formats, and adds support for QuickLook, Time Machine, and Mobile Me. The new version also adds support of additional Zip formats, and has new features for creating smaller archives.

StuffIt Deluxe 2009 can now expand 7-Zip and segmented Zip archives created on Windows or other platforms. StuffIt Version 12 added the ability to further compress already compressed Zip archives, and the ability to compress Microsoft's .docx, .xlsx, and pptx formats, which are essentially Zip files. As with the previous version StuffIt 12 can compress alreadly compressed already compressed graphics formats, including JPEG, PDF, and TIFF. StuffIT uses the .sitx format for compressing these pre-compressed formats.

StuffIt 2009 adds a plugin for QuickLook to enable users to view and read documents that are contained within a compressed archive. This works from the Finder and Time Machine, and other applications. StuffIt can now preview compressed images that come as attachments from within Apple Mail. StuffIt archives can now be searched with Spotlight.

Two utilities included in StuffIt Deluxe 2009, DropStuff and StuffIt Scheduler, can automatically back up archives to iDisk, part of Apple's MobileMe service.

Support for Google's MacFUSE allows users to mount any browsable archive format in the Finder just like a disk or disk image.

DropStuff now is customizable; lets you create drop applets for specific types of compression. You can drag and drop files and folders on top of a drop applet to compress it.

A new feature called Duplicate Folding stores only a single copy of duplicate items within archives, decreasing the size of of the archive. When decompressed, StuffIt will restore the duplicate file.

StuffIt Deluxe is available for US$80 or as a US $30 upgrade from any previous version of StuffIt. StuffIt Standard 2009 (US$50, $15 upgrade) includes only StuffIt Expander and DropStuff (not Scheduler), and can't browse content or extract a single file for an archive, as the Deluxe version can. StuffIf Expander 2009 is also available separately a free download, and adds support for segmented Zip files.

The current Windows version is StuffIt Deluxe 12 for Windows. Smith Micro said that it was planning to release a Windows version of StuffIt 2009 later this year.