One way for extensions to take over control of certain parts of TYPO3's core is using hooks. This article gives an example of how to register your own userfunction at an existing hook and shows the best practice for using hooks in general.

When it comes to links in frontend plugins, some pitfalls arise which circumvent other vital mechanisms like the “L” flag for multilingual websites and thus creates conflicts while using your extension within the TYPO3 framework. This article demonstrates how to use TYPO3's various API functions for link generation.