Backdrop is an open-source content management system (CMS) derived from Drupal 7, offering a user-friendly interface, customisable content types, taxonomies, views, theming capabilities, extensibility through modules, and regular security updates.
cdnjs is a free distributed JS library delivery service.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Open Graph is a protocol that is used to integrate any web page into the social graph.
OpenStreetMap is a free, editable map of the whole world that is being built by volunteers largely from scratch and released with an open-content license.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.