Trilight Zone

[thedark]

If you want bitmap graphics, there's GIMP; if you want vector, I
remember something about a Japanese group creating something like GYVE.

But about the publishing itself, that is, page creation and typography,
there are at least TeX and Lout. Also you can create documents in SGML,
XML or LaTeX and have a TeX or Lout output.

The easiest way to create documents seems to be using LyX (a LaTeX
editor). But the fine tuning in TeX can be daunting, so you could also
try Lout, which does not have such a beutiful front end as LyX but is an
easier language.