ZZAMBONI  This is a very useful application. On a Mac it suffers from "not looking like a Mac app" (as others have commented) because it is implemented in Java, but in exchange it is cross-platform, so you can easily share mindmaps with users using Windows or Linux. It has a bit of a learning curve, but once you get over it, you can quickly and easily use it to brainstorm, to create outlines, to plan projects or papers, etc.  (Version 0.8.1)

KRUNKOSAURUS  I was very excited to find free "mind map" software, but I found this software grossly unintuitive. Besides the supplied commands documented in the help section, a user should be able to do natural things like double-clicking white space to create a new node, and hooking it in afterwards the way he or she sees fit. My first experience with a "mind map" was with a PC app at work. I don't recall what it was called but I definitely didn't need to read extensive documentation to use it. I will continue my search for good, intuitive mind-mapping software for the mac - paying for it if necessary, and until FreeMind improves, I suggest you do the same.  (Version 0.8)

NADAMAC  It's fantastic to have an application like that for free!

But there's room for improvement, too. The icons are so ugly they look like from a homepage of a 12 years old PC user. And the quality of the German translation is not ready for primetime.  (Version 0.8)

L-I-N-K  FreeMind is an application to recommend. I have tested version 0.8.0 and it feels already like a full featured mind mapping application.

Of course it has to evolve some graphical issues (e.g. icon quality).  (Version 0.8)