OpenGroupware.org is a set of applications for contact, appointment, project, and content management. It is comparable to Exchange and SharePoint. It is accessible using Web interfaces or using local clients via WebDAV, GroupDAV, and CalDAV. Custom applications can be developed using the XML-RPC API. OpenGroupware.org runs on almost every GNU/Linux system.
iCalcreator is a PHP implementation to create, parse, select, and edit iCal calendar files for non-calendar systems like CMS, project management systems, and other applications able to support calendar information like agendas, tasks, reports, todo lists, and journaling data, and able to communicate with calendar applications. iCalcreator features the ability to create, parse, edit, and select calendars and calendar components. It is composed of a single class file with a simple interface, and is oriented around iCal calendar component properties.
DAViCal is a server implementation of the CalDAV protocol for storing calendaring resources (in iCalendar format) on a remote shared server. An increasing number of calendar clients support the maintenance of shared remote calendars through CalDAV including Mozilla Calendar (Sunbird/Lightning), Evolution, Mulberry, Chandler, and various other closed-source products such as Apple's iCal and iPhone. DAViCal supports basic delegation of read/write access among calendar users, multiple users or clients reading and writing the same calendar entries over time, and scheduling of meetings with free/busy time displayed.
The Amberdms Billing System is a Web application that provides accounting, invoicing, service billing, and time keeping functions. It is designed for small and medium businesses. This program is developer-friendly with a SOAP API, as well as being appropriate for ISPs with service usage billing features.
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.
wxRemind is a wxPython-based front/back-end for Remind, a powerful calendar and alarm application. The display features a calendar and daily event list suitable for visualizing your schedule at a glance. Dates and associated events can be quickly selected either with the mouse or cursor keys, and dates in the calendar are color coded to reflect the total duration of scheduled events. wxRemind integrates with an external editor of your choice to make editing of reminder files more efficient, provides hotkeys to quickly access the most commonly used options, and allows popup, sound, and/or spoken alarms.
LibrePlan is a Web application for project planning, monitoring, and control. It is a collaborative tool to plan, monitor, and control projects and has a rich Web interface that provides a desktop-like user experience. All the team members can take part in the planning, which makes it possible to have real-time planning. It was designed for a scenario where multiple projects and resources interact to carry out the work inside a company. It makes it possible to communicate with other company tools, providing a wide set of Web services to import and export data.
XNotesNG is the next generation of XNotesPlus, a full-featured personal information manager. It is plugin driven and includes a Todo Manager, Calendar Manager, Category Manager, and extensive notes system, including features such as text searching, printing, alarms, date and calendar inserts, and categorization by colored projects.