You may have a look at here. In fact NorthGate's Kml Builder WAS a good alternative to GE!
From Northgate's website: Google Earth Plugin has been deprecated to oblivion. Kml Builder is
officially retired (does not work) but for historical purposes the
download will remain available for a little while longer.
Kml Builder makes it easy to create and edit KML External link. files to be viewed in Google Earth.
Places you create with Kml Builder can be emailed to your friends or co-workers and can even be published on the Internet or on Intranets for a broader audience.
Anyone who has Google Earth Desktop installed on their computer can open your created KML files with just a mouse click.
The Kml Builder 3-D Earth Viewer displays houses, the color of cars, and even the shadows of people and street signs. The degree of resolution available is based somewhat on the points of interest, but most land (except for some islands) is covered in at least 15 meters of resolution. Las Vegas, Nevada and Cambridge, Massachusetts include examples of the highest resolution, at 15 cm (6 inches). Kml Builder allows users to search for addresses (for some countries only), enter coordinates, or simply use the mouse to browse to a location.
You can create Placemark and Shared Style balloons by adding images, pictures, YouTube videos, Flash Macromedia files and Internet links.
Kml Builder is perfect if you plan to capture a trip somewhere on the earth by easily adding geospatial points of interest complete with formatted text and styled pop-up balloons.
Key features of Kml Builder include:
- Docked windows in which most windows can be closed.
- Drag/drop KML features within the My Places Tree.
- Expand/collapse KML feature containers when dragging by dragging
over the minus sign to collapse and a container feature text to
expand. Just wait a few seconds and voila!
- Opening KML and KMZ files by using the File » Open Locally, File »
Open From Web submenus or by dragging a file from practically
- Preview your changes directly in Kml Builder or in Google Earth.
- Use in-line or Shared Styles and Style Maps.
- Add local and remote images, photos, flash animation, movies,
interactive games and YouTube videos to your balloons.
- Turn Layers on/off, Sun, Atmosphere and Controls visibility Built-in
XML Editor for editing failing KML files