The libexif project's CVS data is in read-only mode, so the project may have switched over to another source-code-management system. To check, visit the Project Summary Page for libexif and see if the menubar lists a newer code repository, such as SVN or Git.
The CVS data can be accessed as follows.
You can run a per-module CVS checkout via pserver protocol:
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P exif
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P gexif
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P libexif
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P libexif-gtk
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P libexif-testsuite
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P libexif-website
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P libmnote
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P m4
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P m4-macros
cvs -z3 -d:pserver:anonymous@a.cvs.sourceforge.net:/cvsroot/libexif co -P m4m
You can view a list of files or copy all the CVS repository data via rsync (the 1st command lists the files, the 2nd copies):
rsync -a a.cvs.sourceforge.net::cvsroot/libexif/
rsync -ai a.cvs.sourceforge.net::cvsroot/libexif/ /my/local/dest/dir/
If you are a project admin for libexif, you can request that this page redirect to another repo on your project by submitting a support request.