Gnarley trees* is a project focused on visualization of various tree data structures. This web site contains visualizations of

We believe that these visualizations can be used very efficiently as lecture aids. We also hope they will be useful for students for self-study, or simply for exploring various concepts and satisfying curiosity.

You can use these visualizations either online on this site or download a standalone application. (The jar file can be run using the command java -jar gt.jar)

*) 1. Gnarl – a knot in wood 2. “Thy sharpe and sulpherous bolt Splits the vn-wedgable and gnarled Oke.” Shakespeare, W. (1603). Measure for measure, Act II, Scene II. 3. Gnarley – 1970s surfer slang for rad, exceptional, or cool; a step above intense (can be positive or negative), see urban dictionary


To run the jar file and the applets on this page, you need the Java Runtime Environment.


This project is open source. You can contribute via github (send a pull request / create an issue).


Gnarley trees are currently available in English and in Slovak. If you would like to contribute a translation into another language, simply download this file, translate it, and create a pull request.


  • Jakub (kuko) Kováč
  • Katka Kotrlová
  • Pavol (paly) Lukča
  • Viktor (friker) Tomkovič
  • Tatiana Tóthová


Gnarley trees are an open source, free software, and are freely available under the GNU General Public License, version 3. The source code is maintained here.