Minder is a free and open source mind-mapping application for Linux. Using Minder you can create, develop and visualize your ideas. You can create beautiful mind maps using the keyboard and automatic tree layout. It comes with markdown and printer support, customizable themes option and more. Some other features are Quick search, focus mode, zoom in, automatic mind-map saving and more. It is released under GNU General Public License v3.0. You can also add notes, tasks and images to your nodes.