Freeplane is a feature-rich mind-mapping application that's compatible with any operating system as long as it has the Java program installed. This open-source utility enables you to put new ideas on paper, order them in hierarchies connected by lines, and immediately share them with other people.
You might need to have a little experience in working with this type of applications. Some of its editing settings might prove to be a bit difficult to configure, especially the ones from the Preferences panel. However, you can go to the Documentation page from the website of the developer and see if you can find the assistance you need.
The app allows you to import XML files, maps created in the MindManager X5 program, etc. All editing options can be found in the Edit menu located on your status bar. You can add sibling and child nodes to your mind-map, attach notes to your project, move and sort elements, and much more. What's more, you can undo as many project changes as you like.
Once you finish working on your mind-map project, you can export it to a wide variety of formats (JPEG, HTML, XML, etc.) or print the file with just a few clicks.
In my opinion, this program is perfect for users with experience in handling mind-mapping apps. So, you should try a different utility if you're looking for a simpler and more intuitive mind-mapping application.