phlyMail is a groupware, webmailer, and PIM. It offers unlimited nested groups, unlimited POP3/IMAP profiles, quotas, an integrated address book, a calendar with multiple reminders and event repetitions, a file manager with an integrated WebDAV server, the ability to send faxes, SMS support (which lets you send SMS, get reminded of events via SMS, and get email notification via SMS), a bookmark manager, themes, and multilingual support. It uses either sendmail or SMTP to send email, and can handle MIME and SSL connections. Support for IDN (Internationalized Domain Names) is included. Through its modular design, it's easy to add completely new features as modules, which can be plugged into the system.
Cerb is a fast and flexible Web-based platform for business collaboration and automation. It helps you remember anything about anyone, collaborate from anywhere, deftly reply to a flood of email, automate, stay informed, capture feedback, track time, flag opportunities, manage tasks, share expert knowledge, and otherwise execute efficiently.
Xplico is an IP traffic decoder that extracts data from an Internet traffic capture. From a pcap file, it can extracts each email (POP, IMAP, and SMTP protocols), all HTTP content, VoIP calls (SIP, RTP, H323, MEGACO, MGCP), IRC, MSN, and so on. It isn't a packet sniffer or a network protocol analyzer, but rather an IP/Internet traffic decoder or network forensic analysis tool (NFAT).
Elastix is a software appliance that integrates the best tools available for Asterisk-based PBXs into a single, easy-to-use interface. It also adds its own set of utilities and allows for the creation of third party modules. The goals of Elastix are reliability, modularity, and ease-of-use. It also features strong reporting capabilities.
Open-Xchange Server Edition is a multi-tier, small footprint solution that integrates seamlessly into customer’s architectures, enabling smooth start of operation based on services. The Open-Xchange Server Edition supports different Enterprise Linux systems like SUSE Linux Enterprise Server 10, Red Hat Enterprise Linux 5, and Debian Etch. Users are presented with a highly advanced, improved, and intuitive browser based interface that meets all their email, calendaring, tasking, contacts, and document storage requirements. Further integrations like LDAP-support or ADS are possible. It's designed for medium organizations and educational and public administrations that want to have a customizable communication solution.
Hastymail is a full featured IMAP/SMTP client written in PHP. The goal is a full featured yet lightweight Web mail client. After a complete review and rewrite, it provides many improvements over the original code including optional AJAX functionality, improved code organization, a plugin API, CSS and PHP template themes, and much more.
The Taridium ipbx is a complete software-based VoIP PBX system that replaces a traditional proprietary hardware PBX. It runs on Linux without the need for extra software licenses, and is based on the SIP standard. It supports many phones and is available for free in a 5 user version.