Much of today’s internet is built on WordPress: there’s one wordpress site for every 101 people on the planet! It’s free and open-source, extendible as a platform for plugins, relatively secure and reliable.
A large part of its success is based on the fact that it’s open source. Volunteer developers from all over the world contribute to its development.
At WordCamp EU last month in Bulgaria, Andrew Nacin, a lead developer at WordPress, addressed the question of sustaining community participation in the face of increasing complexity.
Want to help build WordPress? Go to Make.WordPress.org.