xdvi. Good for previewing.
The books are blocked into files containing 50 pages.
I am afraid 50 pages will still be too large for many printers.
Some illustrations are so bulky that, unfortunately,
some printers are unable to accept even a small number of pages.
If you need to split up some files, I suggest
As for Adobe's Portable Document Format (PDF), I am still waiting for someone to make a working converter for UNIX machines.