http://grass.itc.it/grass57/source/grass-5.7.0.tar.gz
My suggestion for binary names is to follow rpm conventions (if there are any?):
grass-5.7.0-<binary_version>.<OS/distribution>.<OS/distribution version>.<HW>.tar.gz
For example:
grass-5.7.0-1.suse9.0.i686.tar.gz
grass-5.7.0-1.redhat7.2.i386.tar.gz
grass-5.7.0-3.solaris7.6.sparc.tar.gz
Radim