It is loading up for me, i see a SMF installer page.
Can you try now?
If not, are you behind any firewalls? Many companies/schools/large firewalls(including chinas) block our Free server's IPs.
If you are not sure, open a terminal or command propmpt(on windows press Windows key then R, then type cmd) and type ping muchmush.pcriot.com and tell me if its successful or fails.