Extensions are installable packages which give CiviCRM new functionality, and this directory provides a centralized list of extensions which the CiviCRM community has created.
This listing displays CiviCRM extensions that work on all Content Management Systems (CMS). You can also browse directories of integrations that are made specifically for Backdrop, Drupal, Joomla and WordPress. View newest extensions.
Requires - CiviCRM 5.x, php 5.6
Credit : the Wikimedia Foundation
For example if it is installed on a CiviCRM system it will minify crm-menubar.css. If Stripe is installed it will minify stripe css/js.
The implementation used in this extension is based on https://docs.civicrm.org/dev/en/latest/financial/orderAPI/#transitioning-from-contributiontransact-api-to-order-api