Lindenmayer's work is absolutely wonderful.

Although L-systems are ruthlessly simple, sometimes they are a little unintuitive, because the rewrite rules are in string space, not physical space. A couple of months ago I wrote http://canonical.org/~kragen/sw/dev3/skitch#!rrrrrrrrfffffff...] which I think might be a promising alternative that's maybe easier to understand, although it's less powerful. I haven't figured out how to get a dragon curve out of it yet, but I think it's possible.

If you like L-systems you will almost certainly like https://contextfreeart.org/ as well.