Somewhat-interactive Lecture Streaming Software
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What Is It?

creek is a tool for managing interactive streams for large lectures, with support for viewers to engage with the presenter via text chat and emoji "reactions." It was originally written for MIT's 6.009 (Fundamentals of Programming) during the spring 2020 semester, in response to a move to remote instruction during the COVID-19 pandemic, and it has since been used in a few other classes at MIT as well.

Is It Any Good?


Can I Use It?

Of course! creek is Free/Libre Software, available under the terms of the GNU General Public License version 3+ . The Documentation page has more information about installing and using creek.

Do I Want To Use It?

That's a more complicated question. Depending on your use case, using creek may or may not be a good idea. For one thing, please note that, while it has been used successfully in multiple classes, creek is still offered with no warranty whatsoever. I'll try to provide support if you're having trouble, but I can't guarantee anything.

The following brief list of features might help you decide if creek is right for you. creek allows you to:

All interactions are anonymous, and no logs are kept about student interactions (though a variant that integrates with catsoop is available if tracking user participation is important).


If you want to get in touch, report a bug, offer a suggestion, send a patch, etc, feel free to send me an e-mail at


Thanks to Joel Emer for suggestions and contributions, including a tool to make asking questions easier (mirror for non-mit-persons).

creek is written in node.js, using

RTMP and HLS streaming are enabled by NGINX-RTMP and FFMPEG.

WebRTC streaming is enabled by Janus and FFMPEG.

The emojis used in the reaction section are from EmojiTwo and are licensed under CC-BY 4.0.

creek's logo is licensed under CC-BY 4.0. It was created using modified versions of images by Marc Serre and Daniela Baptista; their original images are licensed under CC-BY 3.0.