MotionSampler is an X Window System, Version 11 client, and requires an X11 server to connect to. This is usually specified by the DISPLAY environment variable. A common setting for the DISPLAY variable is :0, which means that you want to connect to the default X11 server, which is likely the one you want when you log in.
MotionSampler also uses OpenGL and requires the proper X11 extensions for running OpenGL programs. All of this is common to most graphical programs that run on Silicon Graphics workstations and is unlikely to be a problem unless your computer or installation is unusual.
For best results, MotionSampler should run on Silicon Graphics machines with at least 64 MB of memory and proportionate swap and disk space.