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.
cdnjs is a free distributed JS library delivery service.
jQuery UI is a collection of GUI widgets, animated visual effects, and themes implemented with jQuery, Cascading Style Sheets, and HTML.
jQuery is a JavaScript library which is a free, open-source software designed to simplify HTML DOM tree traversal and manipulation, as well as event handling, CSS animation, and Ajax.
Leaflet is the open-source JavaScript library for mobile-friendly interactive maps.
Modernizr is a JavaScript library that detects the features available in a user's browser.
OneSignal is a customer engagement messaging solution.
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.
Twitter is a 'microblogging' system that allows you to send and receive short posts called tweets.
Unpkg is a content delivery network for everything on npm.