Start Here

The Harmony Textbook

An Introduction to Concurrent and Distributed Programming using Harmony

Installing Harmony

A Quick Start Guide

Language Reference

Language features and syntax

Library Reference

Built in modules and libraries

Open Source

Download all the sources

What's New in Harmony?

Changelog & Patch Notes


Requires Python 3.6+

HarmonyLang for VSCode

  • Syntax Highlighting
  • Intelligent Code Completion
  • In-editor Visualizer
  • Automatic Compiler Installation


What is Harmony?

Concurrent programming is hard to get right. A deadlock might occur only once in a million executions, caused by the most esoteric of circumstances. Harmony makes finding those bugs easy.

  • Checks every possible interleaving of processes
  • Detects non-compilance with invariants
  • Provides the shortest path to a failing execution

Learning programming in Harmony should be straightforward to those familiar with Python or similar languages. In addition to our online documentation, we provide a textbook in PDF form with many programming examples including Peterson's Algorithm, reader/writer locks, and split binary semaphores.

Read more


Our Primary Contributors

Robbert van Renesse

Creator of the Harmony Project

Anthony Yang

Compilers & Data Output

William Ma

Compilers & Visualization

Kevin Sun

Design & Documentation

Haobin Ni


Renyu Li

Graphical User Interface

Past Team Members

Shi Chong Zhao


Contact Us


433 Gates Hall, Ithaca, NY 14853


+1 (607) 255-1021