You can check out with cvs -d :ext:SOURCEFORGE_USERID@cvs.mlton.org:/cvsroot/mlton co MODULE The vhosting stuff (so that mlton.org is vhosted at sourceforge) appears to be working fine too. Make sure you have addded your ssh public key at https://sourceforge.net/account/editsshkeys.php orelse you will have to type your password every time.