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.
reCAPTCHA is a free service from Google that helps protect websites from spam and abuse.
Swiper is a JavaScript library that creates modern touch sliders with hardware-accelerated transitions.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.