cdnjs is a free distributed JS library delivery service.
OpenResty is a web platform based on nginx which can run Lua scripts using its LuaJIT engine.
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.
SweetAlert is a JavaScript library that provides alternative alert and modal dialog boxes for web applications, with customisable features, aiming to improve the user interface of the default browser dialogs.