For guile via cvs:

cvs -d :pserver:anoncvs@egcs.cygnus.com:/egcs/carton/cvsfiles login
cvs -z 9 -d :pserver:anoncvs@egcs.cygnus.com:/egcs/carton/cvsfiles checkout guile-core


Once you have a working directory, you can bring it up to date easily and efficiently: 

  Go to the top directory of the source tree. That is, your current directory should be the one containing
`configure.in', `README', and so on. 
  Do the update: 

     $ cvs update