Outdated TYPO3 Version
This documentation refers to an outdated TYPO3 version - either select a supported version or make sure to use a TYPO3 Extended Long Term Support (ELTS) version to continue getting security updates.
Since TYPO3 4.4, the TYPO3 backend relies primarily on ExtJS. As of TYPO3 6.0, jQuery was introduced in the new Extension Manager and is the library of choice for the future. Since TYPO3 7.4, Prototype and Scriptaculous are not packed with the Core anymore. If you need them for your projects, you need to take care of shipping them yourself, preferable by usage of requireJs.