3ddesktop GL/gl.h needed to compile?

[memnok]

hi, im a newb to linux currently running SuSE9.3 (incomplete?) on the machine in question.

im trying to install/setup and run 3ddesktop

after googleing the problem with little success i found a link that pointed be to this forum but the thread had expired or something,
after downloading the tar and doing ./configure everything looks good until the end where it says
checking GL/gl.h usability... no
checking GL/gl.h presence... no
checking for GL/gl.h... no
configure: error: GL/gl..h is needed to compile 3ddesktop

can someone please point me in the right direction, or tell me where to get this GL/gl.h . (and maybe telll me what this GL/gl.h is in the first place if youre feeling generous) THanx for your time and help
-memnok

[memnok]

i did more research and installed the gl lib. I also now have some idea if what it is.
(libs for graphics and/or games) however now i need XextCreateExtension in -lXext.

well im back to stfw

any pointers would still be appreciated