What software could I use to rapidly and easily create trees like this:
Looking for freeware. Please supply screenshots where possible. Mind maps are OK as soon as they look like a tree.
Windows and/or Linux. Web-based is great!
FreeMind is a premier free mind-mapping software written in Java. (and thus works on all platforms where the Java Runtimes are installed).
I'm not sure if it's exactly what you are looking for, but Graphviz is good for producing graphs.
It's actually a text format. Here's the code that produced the picture: