HyperText Markup Language (HTML) is the main markup language for web pages. HTML elements are the basic building-blocks of webpages. wikipedia.org

Ruby on Rails, often shortened to Rails or RoR, is an open source full-stack web application framework for the Ruby programming language. wikipedia.org

React is an open-source JavaScript library for creating user interfaces that aims to address challenges encountered in developing single-page applications. wikipedia.org

Cascading Style Sheets (CSS) is a style sheet language used to describe the presentation (that is, the look and formatting) of a document written in a markup language. wikipedia.org

Bootstrap is a popular HTML, CSS, and JS framework for developing responsive, mobile first projects on the web. wikipedia.org

Node.js is a software system designed for writing highly-scalable internet applications, notably web servers. Programs are written in JavaScript, using event-driven, asynchronous I/O to minimize overhead and maximize scalability. wikipedia.org

GraphQL is a data query language and runtime designed and used at Facebook to request and deliver data to mobile and web apps. wikipedia.org

A blockchain is a distributed database that maintains a continuously-growing list of data records hardened against tampering and revision. wikipedia.org

Git is a distributed revision control system with an emphasis on speed. Git was initially designed and developed by Linus Torvalds for Linux kernel development. wikipedia.org

Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. wikipedia.org

Ruby is a dynamic, reflective, general-purpose object-oriented programming language that combines syntax inspired by Perl with Smalltalk-like features. It was also influenced by Eiffel and Lisp. Ruby was first designed and developed in the mid-1990s by Yukihiro "Matz" Matsumoto in Japan. wikipedia.org

Docker is an open-source project that automates the deployment of applications inside software containers, by providing an additional layer of abstraction and automation of operating-system-level virtualization on Linux. wikipedia.org