Gxktoxk is really cktoxk, which has been renamed by itself.  The programGcopies the ck*.* files (in any given directory) into xk*.* files in theFcurrent directory.  This allows an experimental version of C-Kermit toKcoexist with the standard version.  The resulting xk*.* files must be movedJto their own directory and renamed back to ck*.* using the xktock program,before they can be compiled.