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Python interpreter in JavaScript

Project Description

Jaspy is a Python VM written entirely from scratch in JavaScript with interpreter size and coroutine support in mind. It interprets CPython 3.5 bytecode within the browser and aims to replace JavaScript as main web scripting language.


  • easily extensible with native JavaScript modules (time, dom, …)
  • pluggable integer implementations (JS integers, BigInteger.js, …)
  • suspendable interpreter (coroutine and greenlet support)
  • full support for meta-classes and builtin subclassing


This project is still in an pre-alpha planning state. The APIs are unstable, it is untested and not ready for productive use.

Release History

This version
History Node


History Node


Supported By

Elastic Elastic Search Pingdom Pingdom Monitoring Dyn Dyn DNS Sentry Sentry Error Logging CloudAMQP CloudAMQP RabbitMQ Heroku Heroku PaaS Kabu Creative Kabu Creative UX & Design Fastly Fastly CDN DigiCert DigiCert EV Certificate Google Google Cloud Servers