TYPO3.org is the main developer resource of the TYPO3 project, a free CMS framework released under the GPL. This site provides lots of information about creating sites, writing extensions and developing the core of TYPO3.
WordPress is a state-of-the-art semantic personal publishing platform with a focus on aesthetics, web standards, and usability. What a mouthful. WordPress is both free and priceless at the same time. More simply, WordPress is what you use when you want