Eric Blue has been beating the drum for some time now for a universal mind map file format, to make it easier for users of mind mapping software to easily share their files with one another, no matter what program they use. The emergence of web-based mapping tools makes this need even more urgent, he says in a recent blog post.
As a step in this direction, he has written an applet that can take a MindManager file, convert it to a FreeMind .mm file format and output it using the FreeMind Java or Flash viewer. I tried it with a simple MindManager map that I created for this occasion (unfortunately, I couldn't figure out how to embed it in this TypePad blog, so it's set up as an external link).
The output is fairly simple (because that's the way the FreeMind viewer is designed), but still it's pretty intriguing to think that FreeMind could potentially be used as the "Rosetta Stone" to enable the kind of universal map file access that Eric envisions. Cool!