July 5, 2009 at 12:13 pm #60260
The WordPress software (wordpress.org) is used to power wordpress.com – they are both owned and operated by Automatic. WordPress.com does use advertising in some of it’s blogs, but it also operates a subscription system for premium services.
So it is true free and open source philosophy. The software is free forever (wordpress.org), but they charge for added value services (a hosted blog with premium features).