Does Linux (in tandem with KDE or Gnome) support more than one video card?

I presently use 2 monitors on my desktop and would want to be able to keep this functionality under Linux.

Thanks, and let me know if I'm using a too-narrow-perspective about what Linux is and does.

dual monitor
 

well with the new versions of X11 and xinerama it can be done, but its not nearly as simple as in windows, you have to be comfortable messing around with some very important X files, the most helpful how to that ive found sofar is http://ldp.codehack.com/HOWTO/Xinerama-HOWTO-1.html

im a total newbe and have to admit that i havent gotten this to work yet, but ill get it eventually, so far ive gotten linux to recognize that both cards are there, but im having trouble actually getting x started, anyone know which driver to specify for my ati radeon 64 ddr card?

and can anyone help me out if i give details on my setup?

thanks, freddyg