Google Analytics is a free web analytics service that tracks and reports website traffic.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
Pinterest is an image sharing and social media service designed to enable saving and discovery of information.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
YouTube is a video sharing service where users can create their own profile, upload videos, watch, like and comment on other videos.