cdnjs is a free distributed JS library delivery service.
Contact Form 7 is an WordPress plugin which can manage multiple contact forms. The form supports Ajax-powered submitting, CAPTCHA, Akismet spam filtering.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
Mailchimp is a marketing automation platform and email marketing service.
Open Graph is a protocol that is used to integrate any web page into the social graph.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
OWL Carousel is an enabled jQuery plugin that lets you create responsive carousel sliders.
Progressive Web Apps (PWAs) are web apps built and enhanced with modern APIs to deliver enhanced capabilities, reliability, and installability while reaching anyone, anywhere, on any device, all with a single codebase.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
WordPress is a free and open-source content management system written in PHP and paired with a MySQL or MariaDB database. Features include a plugin architecture and a template system.
Yoast SEO is a search engine optimisation plugin for WordPress and other platforms.