Drupal is a modular content management system, forum, blogging and community engine. It is database driven and can be used with MySQL, MariaDB, PostgreSQL, and SQLite. Its features include (but are not limited to) discussion forums, Web-based administration, theme support, a submission queue, content rating, content versioning, taxonomy support, user management with a fine-grained permission system based on user roles (groups), error logging, support for content syndication, locale support, and much more. It is considered to be an excellent platform for developers due to its clean code and extensibility, and it can also be used as a Web application framework.
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.
EZPX is a lightweight photoblog engine with all the features you need and a user interface you'll love to use. It can be used as a standalone photoblog application or as a Flickr agent. It features an easy installer/upgrader that notifies you when an upgrade is available, support for templates, and much more.
visural-wicket is a useful set of light-weight, loosely coupled components and utilities for the Apache Wicket Web framework. Each component is designed to be easily integrated into any existing Wicket application with minimal dependencies. Each component is also designed to be easily customized to fit a particular system's requirements. Other than components, visural-wicket includes some other utilities that assist in the development of Wicket applications, such as an annotation-based mounting system, model templates, and an automatic "form view mode" component.
Nevede is a Web application to schedule events easily. When you start planning an event with Nevede, each participant can to go to the event's Web page to express availability. The event's page will then show the time slots that are compatible with the schedules of all the participants. Events can be made public or private. Comments can be posted in meeting pages.
Precurio is an intranet portal that gives your organization a single point of access to information while helping to streamline your business processes and workflow. It features an employee directory, content management, comments, instant messaging, events, news, polls, microblogging, and reporting.