Kolab is a groupware system that provides a comprehensive and flexible solution for workgroups. Email, contacts, and group calendars can be managed via the Web, Windows/Outlook, and Linux/KDE. It supports offline synchronization and full seamless support of mixed client environments because the Kolab-XML storage format is fully open and avoids MAPI/TNEF.
Yate is a next-generation telephony engine. While currently focused on Voice over Internet Protocol (VoIP) and PSTN, its power lies in its ability to be easily extended. It supports SIP, H.323, IAX, MGCP, Jingle, Jabber, E1, T1, analogic, robbed bit, ISDN PRI, BRI, and SS7. YateClient is an Instant Messenger and Voice application for Jabber/Jingle IM, SIP, H.323, and IAX VoIP protocols.
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.
Iris is a CGI script, Exim MTA and Dovecot configuration files, and Vagrant and Ansible playbook, supplemented with instructions on building an e-mail server with virtual domain support, authenticated SMTP relay, vacation, SMTP-time malware/spam/over-quota reject, and Web based account and domain administration, including domain-level access control for delegated domain management. It is based on Exim MTA, Dovecot IMAP server, MySQL, Perl, Clamav, SpamAssassin, and Roundcube Webmail.
Horde Groupware Webmail Edition is an enterprise ready browser-based communication suite. Users can read, send, and organize email messages and manage and share calendars, contacts, tasks, and notes with the standards compliant components from the Horde Project. It bundles the separately available applications IMP, Ingo, Kronolith, Turba, Nag, and Mnemo. It can be extended with any of the released Horde applications or the Horde modules that are still in development, like a file manager, a bookmark manager, a forum, or a wiki.
Horde Groupware is an enterprise ready browser-based collaboration suite. Users can manage and share calendars, contacts, tasks, and notes with the standards compliant components from the Horde Project. Horde Groupware bundles the separately available applications Kronolith, Turba, Nag, and Mnemo. It can be extended with any of the released Horde applications or the Horde modules that are still in development, like a file manager, a bookmark manager, a forum, or a wiki.
mbot is an IRC bot coded in C++. Its main advantage is that several bots can run simultaneously in the same process, making it ideal for shells where the background processes are limited, but not the connections. It also features IPv6 support, TCL scripting partially compatible with eggdrop, and lots of modules with the most commonly needed functions.
mpop is a small, fast, and portable POP3 client. Its features include header-based email filtering (filter junk mail before downloading it), delivery to mbox files, maildir folders, or a mail delivery agent, a very fast POP3 implementation, many authentication methods, and good support for TLS/SSL.