I build websites with the open source SilverStripe content management system and its underlying framework; Sapphire. This saves a lot of development time and allows me to offer a full-featured CMS customised to your needs at a very cost-effective rate, with no licensing fees whatsoever.
SilverStripe is designed to be easy to use for its intended audience - everyday people. It deals only with managing and editing website content. All the technical details and configurations are set by the developer outside of the CMS, so you don't have to worry about things that don't concern you.
SilverStripe is produced and maintained by a commercial company and supported by a community of passionate developers. It is free software with all the benefits of a commercial product.