HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Nginx is a web server that can also be used as a reverse proxy, load balancer, mail proxy and HTTP cache.
PHP is a general-purpose scripting language used for web development.
Polylang is a WordPress plugin which allows you to create multilingual WordPress site.
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.
A modest JavaScript framework for the HTML you already have.
Swiper is a JavaScript library that creates modern touch sliders with hardware-accelerated transitions.
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.