You'll find install instructions on the following link: http://wiki.goffi.org/wiki/Salut_%C3%A0_Toi

If you need help, come the SàT official XMPP room: sat@chat.jabberfr.org or join us with a web browser via https://chat.jabberfr.org/converse.js/sat@chat.jabberfr.org 
