You cannot develop "real" extensions without using PHP. This section will cover everything that is needed to develop extensions, how best to proceed with programming them, and what programming guidelines should be observed.
Coding guidelines that you should abide by when developing extensions have been published for TYPO3. Always follow them if you have the intention of making your extension publicly available. This section will give you an overview of the guidelines.
You can view the complete text at http://typo3.org/documentation/document-library/core-documentation/doc_core_cgl/current/view/.
A new coding standard was introduced with version 3.6.0 on which all existing and new extensions should be based.
The following list summarizes the most important standards:
XHTML and CSS compliance must be observed.
Single quotes must be used.
Security problems are to be avoided by using
htmlspecialchars(), intval()
and$GLOBALS['TYPO3_DB']->addslashes...