Apache is a free and open-source cross-platform web server software.
cdnjs is a free distributed JS library delivery service.
Chart.js is an open-source JavaScript library that allows you to draw different types of charts by using the HTML5 canvas element.
Chosen is a jQuery plugin that makes long, unwieldy select boxes much more user-friendly.
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.
MathJax is a cross-browser JavaScript library that displays mathematical notation in web browsers, using MathML, LaTeX and ASCIIMathML markup.
Modernizr is a JavaScript library that detects the features available in a user's browser.
Particles.js is a JavaScript library for creating particles.
PHP is a general-purpose scripting language used for web development.
VK is a Russian online social media and social networking service.