Karl,
I have also begun to favor XMind over Freemind because, well ... it simply looks better. And XM does a few things that FM hasn't been able to yet, like embed images, show map as outline, etc.
And the inline viewer is quite handier.
But lets talk about how you'd like to integrate it!
* As it is now, XMind'd sharing features rely on their own (commercial) server, right? So I am not able to host a shared Map on my own server. And all of the maps I share with the free version are by definition public. Only the commercial version allows me closed-group sharing. All of this on their server.
* their model is much like youtube: You get a string for each shared map and with that chunk of HTML you can embed a map with the viewer into your own HTML pages. However, the viewer and the map stay on their server.
* the online viewer currently can only show a file, not edit it. (apparently)
Then allow me the question, how would you integrate that into openGoo?
Until there is a free XMind viewer (like there is for Freemind) that can take maps from any other server, i don't think you can do much more than to store the URL to a viewer in your LINKS application. (you can just extract the URL from the "embed" string that they give you. it looks like this:
http://share.xmind.net/_embed/karstenw/fbf-lpzuwue3gh-3/But maybe It exists and I just havent seen it yet?