gFTP is stored in GNOME's CVS repository. For instructions on how to setup your CVS client, you can visit the webpage http://developer.gnome.org/tools/cvs.html for instructions. In a nutshell, you will need to run the following commands (this assumes you are using the bash shell):
export CVSROOT=":pserver:anonymous@anoncvs.gnome.org:/cvs/gnome"
cvs login
cvs co gftp
To compile the CVS code, you will need autoconf, automake 1.4 and gettext installed on your system. To generate a configure script, you will need to run autogen.sh. Once this script is generated, you can follow the normal installation instructions.