phpGroupWare (formerly known as webdistro) is a multi-user groupware suite written in PHP. Its provides a Web-based calendar, todo-list, addressbook, email, news headlines, and a file manager. The calendar supports repeating events. The email system supports inline graphics and file attachments. The system as a whole supports user preferences, themes, user permissions, multi-language support, an advanced API, and user groups.
alph implements and analyzes historical and traditional ciphers and codes, such as polyalphabetic, substitutional, and mixed employing human-reconstructable algorithms. It provides a pipe filter interface in order to encrypt and decrypt block text to achieve transparency. The program is meant to be used in conjunction with external programs that transfer data, resulting in transparent encryption or decryption of information. The program can thus be used as a mail filter, IRC filter, IM filter, and so on.
Gemini is an advanced, multi-platform, standards compliant, messaging and calendaring client with powerful features for managing mail and news from multiple sources. Gemini provides flexible filtering of messages and protection from junk mail, viruses, and common breaches of netiquette. It has an attractive interface which is easy to use, yet hides nothing from the more advanced user. Additional features include mailing lists as pseudo-newsgroups, message templates, auto-replies, support for multiple identities, HTML, IMAP, SSL, editing of stored messages, spell checking, syntax coloring, and encryption/signing via integration with GnuPG.