If you are looking for a command line utility that can fix your planets checksums, you can find it here
The Echoview guide takes the player through every feature that Echoview has to offer and gives good tips on which features enhances game play the most. You might also learn something that you did not know existed. I know I did :). Find it here.
This guide was written to display the features and abilities of the JVC client for VGA Planets. It handles all the features with some good tips on play and shortcuts in there. You can read it here.
The starmap online viewer is a php script that reads the starmap file and display it online. It can display the planet names as well as the 81Ly links between planets. At the moment it is not possible to upload custom maps for display. You can view it here.
You can find the selection setup for UnNatural 6 here.