The building maintenance scheduled for Friday February 27th at 5:00pm MST has been postponed until 5:00pm March 6th. PSD's website will be down during the maintenance.
 

Community Portal for Accessing National Weather Service Global Weather Model Codes

PSD no longer supplies the GFS source code. You can try contacting NCEP directly for their latest version of the GFS model:
http://mag.ncep.noaa.gov.