what does the evolutionmod client make

what does the beta client thingie do exactly? Can someone tell me exactly how to install it and make it work properly?

I'm not sure if I can go SSJ2 and further in this one, so can someone tell me exactly what this do by any chance?

evolutionmod is what might i ask? ive never heard of it, if its client side esf than u need it to play online, linux is to make dedicated servers