LibreNMS is an autodiscovering PHP/MySQL-based network monitoring system forked from Observium. It aims to be easy to use and painless to deploy, and to support monitoring of a wide range of devices. Observium's license changed to a modified QPL license in May 2012, then was split into free and commercial versions. The aim of LibreNMS is to continue to create a usable NMS, but with a community focus and GPL licensing.
Brimbox is a database system that was designed to bridge the gap between spreadsheets and custom databases. It is intended to be an alternative to Access and Filemaker. Although Brimbox has its own modular approach, it is customizable in the spirit of Wordpress, though it is a database interface and not a CMS.
Open School Admin (OSA) is a Web-based school administration system primarily focused on ease of use and access to school information. It has been in continuous use and development for the past 7 years. It manages all aspects of school administration: student enrollment, class scheduling, mark reporting, attendance, user accounts, and room booking. Through the use of various plugins, it also manages email announcements (including automated attendance notices), government reporting, dorm room management, Alumni relations, etc. It is a standalone application written using a Perl/MySQL back end. It requires a Web server (Apache/Lighttpd tested) and should run out of the box on any Unix system. While OSA itself is very mature, the installation and setup is still a young and evolving process.