This branch contains some fixes to support Twig 1 and PHP 8.1 in my legacy apps. I have not tested the entire framework, so there is no guarantee that it will work for you.
https://github.com/Laiter/Slim-2-php-8.1
Twig is a template language for PHP, released under the new BSD license (code and documentation).
Twig uses a syntax similar to the Django and Jinja template languages which inspired the Twig runtime environment.
Twig version 1 is not maintained anymore. Please, upgrade at your earliest convenience.
Read the documentation for more information.