Open Source

Introduction

Twitter is built on open source software, from the back-end to the front-end. Twitter engineers use, contribute to and release a lot of open source software. We of the Twitter Open Source Program Office support a variety of open source organizations and are grateful to the open source community for their contributions, and want to maintain our healthy, reciprocal relationship.

If you have questions or problems, please tweet us at @twitteross. For media inquiries, please go here.

Development

If you're interested in the projects we have released, check out our official organization on GitHub.

If you want to stay up to date, please follow our official twitter account.

Like what we do? Then consider finding a job you're passionate about and come @JoinTheFlock!

From the Beginning

We have built atop open source software (including MySQL, Ruby on Rails and Memcached) from the company’s start in 2006. Twitter rapidly evolved from a simple application into a service-oriented architecture, leading us to integrate even more open source technologies such as OpenJDK (JVM), Netty, Apache Lucene, Apache Thrift, Apache Hadoop and Redis.

We Contribute to Key Projects

Our engineers are eager to contribute back to the open source community. We have a long history of making existing open source projects more usable, scalable, and robust including:

And We Also Create Our Own Projects

The Twitter Engineering team has grown dramatically in the past few years. We want to continue to grow our company in a way that makes us proud. As a reflection of our core values, we routinely share our innovations with the broader software community. Here are just some examples of the projects we have released as open source:

If you’re interested in helping us build and contribute to these projects, we’re hiring!

Code and Documentation Licensing

The majority of open source software exclusively developed by Twitter is licensed under the liberal terms of the Apache License, Version 2.0. The documentation is generally available under the Creative Commons Attribution 3.0 Unported License. In the end, you are free to use, modify and distribute any documentation, source code or examples within our open source projects as long as you adhere to the licensing conditions present within the projects.

Also note that our engineers like to hack on their own open source projects in their free time. For code provided by our engineers outside of our official repositories on GitHub, Twitter does not grant any type of license, whether express or implied, to such code.