TYPO3 CMS has the following subprojects:

TYPO3 Core

The TYPO3 Core Team takes care of the further development of TYPO3 Core. Look here for the Core bug tracker.

Community Extensions

Many extensions from community members are maintained by them in this section.

You can as well register a project for your extension!

Official Documentation

The project where all the TYPO3 Official Documentation is managed.