openDCIM is a Web-based data center inventory application which allows you to manage capacity and track assets throughout multiple data centers. There are some graphical elements to the system, but overall, the system is designed for keyboard-friendly (rather than click-happy) use. It is written in PHP and utilizes a MySQL backend for ease of deployment on nearly any LAMP-based build.
openQRM is a data-center management and cloud computing platform. Its fully pluggable architecture focuses on automatic, rapid, and appliance-based deployment, monitoring, high-availability, cloud computing, and especially on supporting multiple virtualization technologies. openQRM is a single-management console for a complete IT infrastructure and provides a well-defined API which can be used to integrate third-party tools as additional plugins.
openpom is a Web interface based on NDO for Nagios or Icinga. It allows you to view almost everything about Nagios or Icinga in a single page: alert, ack, downtime, comment. You can also interact with Nagios or Icinga through ack, downtime, comment, disable, and reset buttons. You can filter on hosts and services states (such as critical, warning, unknown, ok, or outage). The status popin allows you to display graphs, either the ones from Nagios (trends.cgi) or custom ones based on RRD (such as pnp4nagios).
OpenUCF is a unified communications/VoIP framework for PHP5 supporting telephony, presence, and other communication-related features. It has a Web interface for users and administrators. It features a RESTful API, rich-presence, VoIP/SIP based on Asterisk, and XMPP presence based on jabberd2.
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.
phpCacheAdmin is a Web application for administrating and debugging Memcached. It allows you to delete or view the current contents of the server and specify the output cache time. It also has the potential to be expanded to xDebug, FileCache, radishes, and other types of caches.