This page will become a master list of distribution and material available for installing Linux.
Right now the most stable Linux platform for EMC is the Red Hat 5.2 distribution. While you may have some trouble finding it, this distribution is well worth the search if what you want to do is make chips with your converted machine tool.
Dave Anderson had a number of copies of a public domain version at NAMES in 2000. You might ask if he has them still. He also had a collection of EMC info on a second CDROM. You could ask if he has either of these available by posting to CAD_CAM_EDM_DRO@yahoo.com.
There are a couple of ZipEmc distributions that have been made. These use a windows file system so that you do not have to re format an existing ms windows machine. If you are interested in one of these post a request to emc@nist.gov and someone should answer with a current source for these CD's.
The newer releases of Linux produce mixed results. A large part of this seems to stem from the specific compiler and glibc that is shipped with the distribution. There are several pages in the handbook that were written by Ray Henry that detail the installation of real time and EMC while using a Mandrake 7.0 distribution. You should look for these under rtlinux and EMC.