MindMup is a free mind mapping tool that can be used online, with Google Drive, and on your desktop. MindMup works like most mind mapping tools in that you can create a central idea and add child and sibling nodes all over a blank canvas. MindMup nodes can contain text and links.
When you're ready to save your MindMup mind map you can save it to Google Drive, save it to your desktop, or publish it online. If you publish it online, you can grab an embed code for it to post it in a blog post or webpage.
Applications for Education
I've often had my students create mind maps as an exercise in making visual connections between important concepts, events, and people in a unit of study. MindMup can be used by any student without the need to create an account. That makes it suitable for students who don't have email accounts to use. MindMup mind maps that are published online can be made into collaborative exercises. Consider starting a MindMup mind map with a central idea and then share it with your students to complete as a group.
H/T to Lifehacker.