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.
Bootstrap is a free and open-source CSS framework directed at responsive, mobile-first front-end web development. It contains CSS and JavaScript-based design templates for typography, forms, buttons, navigation, and other interface components.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
PHP is a general-purpose scripting language used for web development.