- [Mailpile](https://www.mailpile.is/) - Webmail client with search, filtering, encryption features and more. ([Source Code](https://github.com/mailpile/Mailpile)) `AGPL-3.0``Python`
- [RainLoop](http://www.rainloop.net/) - Simple, modern and fast webmail with IMAP/SMTP Support and multi accounting. ([Demo](http://demo.rainloop.net/), [Source Code](https://github.com/RainLoop/rainloop-webmail)). `AGPL-3.0``PHP`
- [Roundcube](https://roundcube.net) - Browser-based IMAP client with an application-like user interface. ([Source Code](https://github.com/roundcube/roundcubemail/)) `GPL-3.0``PHP`