Many programs seem to be very slow on 2D graphics output, e.g. on implementing transparency, scrolling, etc..
How can i make all (or most of) the calls to graphic libraries use OpenGL?
I read about cairo's support of output to OpenGL context in wikipedia, and found out that i need glitz to use this feature. I installed glitz and then tried to compile cairo with --enable-glitz command line argument for configure script. configure says:
Does this mean cairo is going to use its own version of glitz, included in cairo's package, instead of using already installed one? If yes, how can i then make cairo use really working glitz?

Or, maybe glitz for cairo doesn't make much sense to speeding up 2D graphics in X server? I also read about Xgl in wikipedia, but in that article there was a link to AIGLX... Now with all this info i'm confused with this topic... Maybe, nothing of mentioned above would solve my task? What could be the solution then?

I think you are looking in the wrong place.

I had much the same problem with slow 2D performance on my older AGP based linux system. It had a Nvidia FX5200 card on an AGP slot, I solved the problem by loading the binary closed-source Nvidia driver onto that system. 2D performance was fixed after this step.

I suspect your problem is much the same, i. e. the X windows driver for your card is using software only, with no acceleration because no applicable firmware driver is loaded for your display card. That is why it is so slow...

I use nVidia proprietary driver version 173.08, there's no problem in driver's hardware acceleration support - i play 3D games at very high frame rate, video card is not old also - GF8800.