Click on the 'code' tab from this
link.
Or just go to this
link and follow instructions for 'Anonymous CVS Access'
Checking the code out from the CVS repository gets you the latest source containing features & bug fixes that aren't in the current tar ball.
Once the code for paclink-unix is checked out read the INSTALL.CVS file
sudo apt-get install cvs
cvs -d:pserver:anonymous@paclink-unix.cvs.sourceforge.net:/cvsroot/paclink-unix login
(just hit enter for the password)
cvs -z3 -d:pserver:anonymous@paclink-unix.cvs.sourceforge.net:/cvsroot/paclink-unix co -P paclink-unix