The document TYPO3 Extension Development is a guide mainly for extension developers, explaining the basic steps to create an extension and going further into advanced topics useful for TYPO3 extension development.
t3-module development starting point
TYPO3 - Version 4.0 freigegeben
Die CMS Drupal, eZ Publish, Plone, Joomla und Typo3 im subjektiven Featurevergleich
Mit dem Kickstarter eine Extension erstellen