- [OTS](https://ots.fyi/) - One-Time-Secret sharing platform with a symmetric 256bit AES encryption in the browser. ([Source Code](https://github.com/Luzifer/ots)) `Apache-2.0``Go`
- [Papercups](https://papercups.io/) - An open source live customer chat web app written in Elixir. ([Demo](https://app.papercups.io/demo), [Source Code](https://github.com/papercups-io/papercups)) `MIT``Elixir`
- [PushBits](https://github.com/eikendev/pushbits) - Self-hosted notification server for relaying push notifications via Matrix, similar to PushBullet and Gotify. `ISC``Go`
- [PushBits](https://github.com/pushbits/server) - Self-hosted notification server for relaying push notifications via Matrix, similar to PushBullet and Gotify. `ISC``Go`
- [Rallly](http://rallly.co) - Rallly is a free collaborative scheduling service. ([Source Code](https://github.com/lukevella/Rallly)) `CC-BY-SA-4.0``Nodejs`
- [RetroShare](http://retroshare.org) - Secured and decentralized communication system. Offers decentralized chat, forums, messaging, file transfer. ([Source Code](https://github.com/RetroShare/RetroShare)) `GPL-2.0``С++`
- [Rocket.Chat](https://rocket.chat/) - Teamchat solution similar to Gitter.im or Slack. ([Source Code](https://github.com/RocketChat/Rocket.Chat)) `MIT``Nodejs`