Hello,
there is no Xgrass distribution on topquark, because
Andy Burnett has no Motif License.
I will put an Xgrass-port to Linux on ftp.uni-erlangen.de
soon, but be aware, Xgrass on Linux will not run properly!
Try tclgrass instead of Xgrass, You will find Xgrass-source
and tclgrass besides the whole GRASS source on moon.cecer.army.mil