I've found Ramiro Gallo in Facebook, where we have shared some experiences around Ubuntu.
Just like in Windows, we don't need to install xMind, because we can use it as a portable SW.
But, in my case, then xMind file was not opening because I didn't have the JAVA JRE installed in my ubuntu.
So to install JAVA JRE I have used the following code in terminal as super user:
sudo apt-get install default-jre
When the install was finished, I've got inside the XMind folder... ../XMind_amd64/ and executed the file XMind
Everything is working well now.
Tks Ramiro for your support.
I hope this post help another people just like us.
Regards.
Robson dos Anjos