BackPress is a PHP library of core functionality for web applications. It grew out of the immensely popular WordPress project, and is also the core of the bbPress and GlotPress sister-projects.
It includes a variety of the foundations you need to build robust, scalable web applications including (amongst other things):
* Logging,
* User Roles and Capabilities (Permission systems),
* Database connections (across multiple servers and multiple datacenters),
* HTTP Transactions,
* XML-RPC Server and Client,
* Object caching,
* Formatting,
* XSS and SQL injection protection, including a variety of powerful escaping functions,
* Taxonomies and
* Options management