cdnjs is a free distributed JS library delivery service.
Cloudflare is a web-infrastructure and website-security company, providing content-delivery-network services, DDoS mitigation, Internet security, and distributed domain-name-server services.
Google Ads Conversion Tracking is a free tool that shows you what happens after a customer interacts with your ads.
Google Analytics is a free web analytics service that tracks and reports website traffic.
PHP is a general-purpose scripting language used for web development.
Select2 is a jQuery based replacement for select boxes. It supports searching, remote data sets, and infinite scrolling of results.