“Primitive” might be the wrong word. What tool might I create simple, instructive pictures for a technical topic like, for example, the Understanding VC-1 Wiki page? Sometimes, a picture explains an algorithm better that a wall of bulleted text. Ideally, this would be a tool that runs under Linux and is free. Open source is is nice, on principle, but in this case I’m more interested in something that works already so I don’t have to modify it.
xfig?
Wow, that’s primitive alright, [maven]. :) Primitive-looking, at least. But it seems to be quite feature-rich. I will try it out and see if I can draw what I’ve been thinking about.
If you don’t want wysiwyg metapost might work well. Even neater would be embedding metapost code inline in the wiki.
I just noticed that OpenOffice, which I already have installed, has a Draw component which may be worth looking into.
xfig works fine once you get used to it.
I’d use inkscape
I found useful to write primary disagrams in XFig and do further editing/adjustments in Inkscape and/or Sodipodi (it’s hard to install Inkscape onto my rather ancient computer).
BTW, I don’t know present situation but I used specially patched fig2dev (patched by me) to produce correct SVGs, standard one writes incorrect information for circles and picture metrics are way too big.
xfig is very good and what I have used for many years
in all my published work and teaching material.