- [phpBB](https://www.phpbb.com/) - Flat-forum bulletin board software solution that can be used to stay in touch with a group of people or can power your entire website. ([Source Code](https://github.com/phpbb/phpbb)) `GPL-2.0``PHP`
- [PixelFed](https://pixelfed.social) - Pixelfed is an open-source, federated platform alternate to Instagram. ([Source Code](http://github.com/pixelfed/pixelfed)) `AGPL-3.0``PHP`
- [Pump.io](http://pump.io/) - Stream server that does most of what people really want from a social network. ([Source Code](https://github.com/e14n/pump.io)) `Apache-2.0``Nodejs`
- [Pump.io](http://pump.io/) - Stream server that does most of what people really want from a social network. ([Source Code](https://github.com/pump-io/pump.io)) `Apache-2.0``Nodejs`
- [remark42](https://remark42.com/) - A lightweight and simple comment engine, which doesn't spy on users. It can be embedded into blogs, articles or any other place where readers add comments. ([Demo](https://remark42.com/demo/), [Source Code](https://github.com/umputun/remark)) `MIT``Go`
- [Satellity](https://satellity.org/) - Yet another open source forum written in Golang, React and PostgreSQL. ([Source Code](https://github.com/satellity/satellity)) `MIT``Go`
- [Scoold](https://scoold.com) - Stack Overflow in a JAR. An enterprise-ready Q&A platform with full-text search, SAML, LDAP integration and social login support. ([Demo](https://live.scoold.com), [Source Code](https://github.com/Erudika/scoold)) `Apache-2.0``Java`