The source code can be downloaded from here:

The Original Source
HoverRace SVN Repository - posted 29/11/2008

Here is the license it is under:

GrokkSoft HoverRace SourceCode License v1.0, November 29, 2008

Redistribution and use in source and binary forms, with or without modification,
are permitted provided that the following conditions are met:

- Redistributions in source code must retain the accompanying copyright notice,
  this list of conditions, and the following disclaimer.
- Redistributions in binary form must reproduce the accompanying copyright
  notice, this list of conditions, and the following disclaimer in the
  documentation and/or other materials provided with the distribution.
- Names of the copyright holders (Richard Langlois and Grokksoft inc.) must not
  be used to endorse or promote products derived from this software without
  prior written permission from the copyright holders.
- This software, or its derivates must not be used for commercial activities
  without prior written permission from the copyright holders.
- If any files are modified, you must cause the modified files to carry
  prominent notices stating that you changed the files and the date of any

  The author makes no representations about the suitability of this software for
  any purpose. It is provided "AS IS", WITHOUT WARRANTIES OR CONDITIONS OF ANY
  KIND, either express or implied.

Code away!