In SISSA you can have a personal web page, reachable as http://people.sissa.it/~yourusername/
There is a script, usable on the Common Access server, that automatically creates your generic home page:
sissa-mkhome
But, if you prefer to manually perform all necessary operations, you have to:
mkdir $HOME/public_html
chmod a+rx $HOME/public_html
chmod a+x $HOME
chmod a+r $HOME/public_html/*.html