- [BigBlueButton](https://bigbluebutton.org/) - Supports real-time sharing of audio, video, slides (with whiteboard controls), chat, and the screen. Instructors can engage remote students with polling, emojis, and breakout rooms. ([Demo](https://demo.bigbluebutton.org/gl), [Source Code](https://github.com/bigbluebutton/bigbluebutton)) `LGPL-3.0``Java`
- [BigBlueButton](https://bigbluebutton.org/) - Supports real-time sharing of audio, video, slides (with whiteboard controls), chat, and the screen. Instructors can engage remote students with polling, emojis, and breakout rooms. ([Demo](https://demo.bigbluebutton.org/gl), [Source Code](https://github.com/bigbluebutton/bigbluebutton)) `LGPL-3.0``Java`
- [Conference Organizing Distribution (COD)](http://usecod.com/) - Create conference and event websites built on top of Drupal. ([Source Code](https://git.drupalcode.org/project/cod)) `GPL-1.0``PHP`
- [frab](https://frab.github.io/frab/) - web-based conference planning and management system. It helps to collect submissions, to manage talks and speakers and to create a schedule. ([Source Code](https://github.com/frab/frab)) `MIT``Ruby`
- [indico](https://getindico.io/) - A feature-rich event management system, made @ CERN, the place where the Web was born. ([Demo](https://sandbox.getindico.io/), [Source Code](https://github.com/indico/indico)) `MIT``Python`