Late last evening, Apple released an update to the third developer preview seed of OS X Mountain Lion, bringing the build number up to 12A193i. The update is available via Software Update for those developers already running Developer Preview 3 of Apple's next desktop operating system.

We're currently gathering a list of changes in this build and will update as we find them.

UPDATE: Changes follow:

• First look at the update installation screen under OS X Mountain Lion

• Simplified "General" preference pane in System Preferences

• New "Do Not Disturb" option found in Notification Center

• New "Group windows by application" option in Mission Control preferences

• Safari's "Reading List" feature has received a design refresh

• Safari's Reading List feature now supports offline reading. Any page added to the Reading List will be saved automatically for offline reading
• Safari's redesigned "iCloud Tabs" feature

• The background image used in Dashboard has been modified