This is Celestia executable for Windows (32bits), built from the SVN repository. Unpack it into your own Celestia SVN folder.
Celestia 1.6.0 has been released. You don't need this executable unless you are desperate to try the most recent development changes. Use it at your own risk.
Celestia development has stopped. These are the latest builds, from several year ago. There is a spin-off, Celestia.Sci, without public releases yet.