The first time, create a directory 
$GAMGI to store everything related 
with GAMGI, typically 
~/gamgi (in user space), or 
/usr/local/gamgi 
or 
/opt/gamgi (in root space). Because GAMGI is in heavy development 
and new versions are coming up all the time, we strongly suggest to create 
this directory in user space, making it easier to install new versions and 
reducing concerns with security. In any case, GAMGI should be downloaded, 
compiled and installed by a user, not by root. From now on, everytime we 
mention 
$GAMGI, this should be replaced by the apropriate directory.
Create the $GAMGI directory
mkdir $GAMGI
Download to $GAMGI the file
gamgi-all-version.tar.gz (source code, documentation, data)
Unpack the file
cd $GAMGI
gunzip gamgi-all-version.tar.gz
tar -xvf gamgi-all-version.tar