Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Nucleus CMS is an open-source blog management software package written in PHP, with a MySQL backend, primarily written and maintained by Wouter Demuynck. It is used to manage frequently-updated Web content. With a little tweaking, it might be considered a lightweight content management system. Nucleus makes use of a callback function which has led to a plugin system that has inspired somewhere in the order of 50 to 100 distinct plugins. The general drive within the development community is that functionality should exist as plugins as totally as possible. This philosophy has led to a relatively light and uncluttered base install. Nucleus is included in Fantastico, available via many domains' cPanel as well as via a number of "easy install" services such as Simple Scripts.