Changes in Version 4.2.0180:

• Added Traditional Chinese language support
• Sky viewing mode, including search and high-resolution astronomical images
• Photo navigation and placement modes, including high-resolution tiled photo support
• Embed tag with Flash in placemark balloons (Windows only)
• Icon palette changed to match Google Maps
• End User License Agreement moved from the installer to the download page
• Expanded terms of service for Free and Plus products
• Embedded flight simulator
• Support for KML gallery

KML 2.2 Support:

• Reference elements inside KML files with the feature anchor syntax
• New <Camera> element to specify viewing parameters
• New <PhotoOverlay> element for rectangular, cylindrical, and spherical images
• New <ResourceMap> element in <Model> for better control of <Model> textures (replaces the textures.txt file)
• New <maxSessionLength> element of <NetworkLinkControl>
• <ExtendedData> for balloon templating
• Full list of changes at code.google.com/apis/kml/documentation

Major Fixes:

• Improved COLLADA importing
• Allow larger and zero values for icon size, label size, line width
• Garmin USB GPS device support fixed for Mac OS X 10.4.10
• Numerous translation improvements