actually... ignore my previous answer (i wasn't awake yet >.>)
tremulous 1.1.0 is only precompiled for i386 processors, you'll need to either install your distribution's package if they have one, or download the .zip for the data and compile the client yourself.
edit: and before you go through the effort to install tremulous make sure you have working hardware 3d.
Ok so how do i compile the client myself?
I downloaded the zip version of trem but the installer wont start 
unzip the tremulous .zip, unzip the source .zip inside, run make*, copy executable to folder that you unzipped the tremulous .zip to
*you'll need gnu make, gcc, sdl, sdl's headers, opengl, opengl's headers, openal, openal's headers and maybe some other stuff i'm forgetting installed first