What is the OpenGL ES?

I’m interested in 3D graphics programming for PDA machines. I heard that OpenGL ES is developed for the PDA environment.

If I’d like to write a PDA application, based on 3D graphics, what sort of knowledge do I have to know?

Regards,
Alex D.B., Kim

For more information about OpenGL ES :
http://www.khronos.org/opengles/
http://www.khronos.org/devu/opengles_challenge/

Some searches on OpenGL and PDA also returned :
http://www.pocketgear.com/software_detail.asp?id=1858
http://www.handhelds.org/hypermail/familiar/10/1049.html

Your information is really helpful for me.
Thanks a lot,

Alex D.B., Kim