Following the instructions at http://www.haystack.mit.edu/tech/vlbi/mark5/downloads.html:

1. Install the Mark5B Debian Etch distro
2. Install the Mark5B OS application disk

Install fuseMk5A according to fusemk5

Install DiFX. Edit setup.bash Get a copy of the IPP libraries

apt-get install subversion
svn co https://svn.atnf.csiro.au/difx/master_tags/DiFX-1.5.1/
apt-get install openmpi-bin automake libtool