WordPress is an open source content management tool and internet publishing platform powered by PHP & MySQL.
This MeetUp group gives presentations and holds discussions about WordPress technical aspects and business applications.
WP can be used under wordpress.com as a simple blog. Or, download the code from wordpress.org and customize your own Content Management System. It has many dynamic features, including a plug-in architecture and a template system.
WordPress-Saratoga's twitter handle is @saratogameetup