This package contains the Pimcore 4 compatibilty bridge, which adds the ZF1 dependency and some classes to provide a fallback/bridge onto the ZF environment in Pimcore 5 projects. By using this package, you can gradually migrate your Pimcore 4 projects (Zend Framework) to Pimcore 5 (Symfony).
Install the compatibility bridge package:
$ composer require pimcore/pimcore4-compatibility-bridge --no-scripts $ composer update
Follow the Installation docs for further steps.