WordPress is an open source, PHP-based content management system for the web, developed by the WordPress core community.
Get latest major version, or clone the git mirror of alpha development: git://develop.git.wordpress.org.
WordPress + Memcached An overview of caching in WordPress.
Evan Solomon's "Fast WordPress"
See also Web Servers > Caching, HTTP > Caching and PHP > Caching.
WordPress Memcached Object cache Use the WordPress object cache API with Memcached.
Debug Bar Add a debug menu to the admin bar that shows query, cache and other helpful debugging info.
Debug Bar Console Add a PHP/MySQL console to the debug bar.
Query Monitor Adds debug output including: all DB queries, all hooks and their callbacks, PHP errors, constants, WP_Http requests.
WPDB Migrate Pro Sync DB content between WordPress installs. Requires a paid license.
Standalone libraries that can be included with plugins or themes.
Posts 2 Posts Create relationships between posts, pages, custom post types, and users.
Custom Metaboxes and Fields Create admin UI for post metadata.
Memcached Object Cache Use Memcached as an object cache. Requires Memcached, see 1.
Mercator Multisite domain mapping for the modern era (requires 3.9+). A sequel-plugin to WPMU Domain Mapping.
Require Login Limit front-end access to logged in users.
Gravity Forms offers UI for administrators to create forms with ease and output them on the front-end. Requires a paid license. Not easily extensible in some regards, and development takes place in a closed community.
WordPress' development philosophies were inspired by Havoc Pennington's writings
- 1 Memcached is not available in common shared environments or the core PHP install, as it is a PECL extension. For installation, see "How to install and use Memcached on Ubuntu 12.04"