Introduction

Fluid is a PHP-based templating engine for web projects. In contrast to other templating engines, it uses an XML-based syntax in its templates, which allows template authors to apply their existing HTML knowledge in Fluid templates.

Fluid originated in the TYPO3 and Neos ecosystem before it was extracted from these projects into a separate PHP package. While its main usage nowadays is within TYPO3 projects, it can also be used as an independent templating language in PHP projects.

In Fluid, all dynamic output is escaped by default, which makes the templating engine secure by default. This prevents common XSS (Cross Site Scripting) mistakes that can easily happen in HTML templates.

Fluid comes with a range of so-called ViewHelpers that allow various formatting and output modification directly in the template. Custom logic can be added by providing custom ViewHelper implementations through a straightforward PHP API.