Extension development 

Learn about the concept of extensions in TYPO3, the difference between system extensions and local extensions. Learn about Extbase as an MVC basis for extension development.

Lists reserved file and directory names within an extension. Also lists file names that are used in a certain way by convention.

This chapter should also help you to find your way around in extensions and sitepackages that were automatically generated or that you downloaded as an example.

A site package is a custom TYPO3 extension that contains files regarding the theme of a site.

Learn about tools that help you to create a new Extension or add functionality to an existing extension.

Helps you kickstart your own extension or sitepackage. Explains how to publish an extension. Contains howto for different situations like creating a frontend plugin, a backend module or to extend existing TCA.

Extbase is an extension framework to create TYPO3 frontend plugins and TYPO3 backend modules.

Explains how to pick an extensions key, how things should be named and how to best use configuration files (ext_localconf.php and ext_tables.php)

Contains tutorials on extension development in TYPO3.