The Turtle System

The Turtle System is a free educational program developed at the University of Oxford, designed to support the new Computer Science component of the National Curriculum, and to bridge the “Post-Scratch Gap” between visual programming systems like Scratch and text-based programming. It supports several languages, all of which are compiled to portable code for a virtual Turtle Machine. The workings of the compilers and of the Turtle Machine are all open to inspection, providing many additional learning opportunities for advanced students.

Download for Windows

The Turtle System

The Turtle System is available as a traditional desktop app for Windows, downloadable from the button above. No installation is required; simply double-click the file to run it. The first time you run the program, Windows may warn you that it is of unknown origin, and therefore potentially unsafe. To run it, click ‘More Information’ and then ‘Run Anyway’.

Version 15, which includes Turtle Python, is significantly more powerful than earlier versions, but currently (Autumn 2023) at a "beta" stage of development, and undergoing thorough testing. For this reason, version 14 (which includes Turtle BASIC and Turtle Pascal, but not Turtle Python) remains available.

Run Online and on other Platforms

The Turtle System is also available as a progressive web app, which can be run directly in your browser (click on Run in the main site menu), and installed for offline use (look for the ‘+’ icon in your address bar or the ‘Add to Home Screen’ prompt on your phone’s browser). This version currently supports more languages than the desktop application, but does not yet support file handling. When file handling is implemented, it will enable reading and writing files to your personal space on our server, which is created for you when you register for an account on this site.

Further Information

Please see the Documentation section for programming guides and information about how to use the Turtle System. For a discussion of the principles behind the System, see the About page, or Peter Millican’s articles in Computing at School’s SwitchedOn magazine.

For any additional information, or to make suggestions for future developments, please contact us.