GD is available as a free download from Google and does require Mac OS 10.4. The update process will require a reboot and reindexing your drives to support the new languages; however, Google has changed the architecture of the search utility so that future updates should not require rebooting. The full change list is in the rest of the post.
Release Notes --
Version 126.96.36.1990 (8/31/2007)
We've improved the following features:
Support for 9 new languages (English UK, French, Italian, German, Spanish, Chinese Simplified and Traditional, Japanese, and Dutch).
Support for non-English and non-Roman languages, especially Japanese.
Support to ignore email identified as spam in Mail and Entourage.
Support for contact groups in Address Book and Entourage.
Split kernel extension into two parts to avoid future reboots on Tiger.
We've fixed bugs where the following actions occurred:
Cmd-cmd hotkey is tripped accidentally
GoogleDesktopDeamon locking up when trying to send messages to itself
Slow performance when changes are made on a volume not being indexed
Slow performance on files with an extraordinary number of unique terms
Non-google pages would sometimes get OneBox results
The Search Box might not launch after install
Index exists on an external volume but can't be deleted in the preference panel
Renames made to an offline volume were not detected
Search Box not appearing correctly when the display changes
Known Issues :
Updating to version 1.0.4.XXXX may require a reboot and will require all drives to be re-indexed.
During initial indexing, Google Desktop may have a noticeable impact on your computer, especially if your hard drive is highly fragmented or low on disk space. We've designed Google Desktop to be usable - if a bit sluggish - during this period. Once indexing is complete, your computer should return to its normal, speedy self. To expedite indexing, we recommend that you have at least 10% disk space remaining and defragment your hard disk before installing.
Users who have recently upgraded to 10.4.9 may experience unknown errors installing Google Desktop with Google Updater. To resolve this, try to mount any other DMG file; if that fails, please delete /System/Library/Extensions.kextcache and /System/Library/Caches/com.apple.kernelcaches/, then reboot your system.
Mail and Browser Issues
Indexing Gmail may take a long time because emails are downloaded in batches; each 'batch' is separated by two hours, and there's no progress meter.
If you use MailTags, you need to delete the existing MailTags Spotlight importer from /Library/Spotlight or ~/Library/Spotlight and reinstall version 2.0b9 or later. Earlier versions cause crashes during indexing.
If you have a file or folder that has been moved in and out of the privacy list, Google Desktop search will show revisions of the file when it was outside of the privacy list.
We have received reports of some CVS (Concurrent Versioning System) updates failing with I/O errors. The workaround is to disable indexing during update and re-enable after update is complete.
If you're working with programs like CVS or SVN (Subversion), you may experience large amounts of file I/O. There's a known issue in Mac OS 10.4+ where large amounts of file I/O may cause a kernel panic. To resolve the issue, we recommend adding any CVS- or SVN-associated items to your Privacy list.