TurtleLab

About TurtleLab

TurtleLab is a block-based drawing tool. You snap blocks together to tell a turtle where to walk, and it draws as it goes. It runs entirely in your web browser. There is nothing to install, no account to make, and nothing you do is sent anywhere.

It was made by Eric Brown for classroom use, as part of learn.porttack.com.

Read the guide or read the privacy page.

Where the look comes from

TurtleLab's blocks and its turtle are based on Turtle Blocks JS, part of the family of free learning software from Sugar Labs, written by Walter Bender and many other contributors. We adapted its block shape drawing code and some of its artwork (the turtle, the palette icons and some of the toolbar icons), and changed them to fit TurtleLab. Turtle Blocks is free software under the GNU Affero General Public License, version 3 or later.

TurtleLab is not made by, or endorsed by, Sugar Labs.

The block colors come from the same project (copyright Sam Parkinson, GNU General Public License, version 3 or later). The Roboto font is by Google, under the Apache License 2.0. The script, fancy, sans, bold and serif letters for the write block are the Hershey fonts, made by Dr. A. V. Hershey at the U. S. National Bureau of Standards and in the public domain. The blocky letters are EMS Osmotron, a single line font by Windell H. Oskay of Evil Mad Scientist Laboratories, made from Orbitron by Matt McInerney, under the SIL Open Font License (the license text is in the fonts/osmotron folder). The exact list of borrowed files, and what was changed in each one, is in the NOTICE file.

The licence, and the source code

TurtleLab is free software. You can use it, study how it works, change it, and share it. It is licensed under the GNU Affero General Public License, version 3 or later, copyright 2026 Eric Brown. If you share a changed version, even by putting it on a website, you must share its source code under the same licence.

The pictures you make are yours. The licence covers the program, not what you make with it.