The courses of extreme tux racer, or etracer as it is called for short, are quite easy to create. they consist of three graphic files and one textfile.

this package contains some scripts and colour palettes, which make it easy to create the graphic files of etracer courses with the gimp.

details on how to create courses can be found at http://www.extremetuxracer.com/wiki/index.php?title=creating_courses