Ahrefs is an online toolset utilised for search engine optimisation (SEO) and competitor analysis, which permits users to analyse their website's performance, track keyword rankings, identify backlink opportunities, and research competitors' websites, among other features.
HTTP Strict Transport Security (HSTS) informs browsers that the site should only be accessed using HTTPS.
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.
vBulletin is tool that is used to create and manage online forums or discussion boards. It is written in PHP and uses a MySQL database server.
YUI is a JavaScript and CSS library with more than 30 unique components including low-level DOM utilities and high-level user-interface widgets.