AtMail Open
AtMail is an open source webmail client written in PHP. We aim to provide a elegant Ajax webmail client for existing IMAP mailservers, with less bloat and a focus on an intuitive, simple user interface. The open source version of AtMail provides users with a lightweight, yet powerful webmail client. The software can be installed on a variety of platforms with ease and without the hassles that most webmail platforms impart.