the 3d modeling application itself is called blender.
http://www.blender.org/
which is available for free on windows, linux, and mac.
if you are new to blender this might be a good site to look at
http://en.wikibooks.org/wiki/Blender_3D:_Noob_to_Pro
the exporter to vdrift is a python script, so it should work on any platform as well. just drop it into your "blender/.blender/scripts" folder and you should have the ability to export -> .JOE when in blender.
UV texturing changed a bit in the last (2.46) release of blender. but there are tons of blender tutorials out there. here's the one i just used to figure out the 2.46 changes:
http://wiki.blender.org/index.php/Manual...ing_a_Mesh