Free Software for JavaScript
React
React is a free an open-source Javascript framework for frontend development. With React you can build powerful, component-based application that supports compilation of JSX, ES6 and auto-prefixed CSS files. The popular framework is developed by Facebook and used by countless of applications across the web and mobile devices to build structured user interfaces or UI components.
Nuxt.js
Nuxt.js is an intuetive Vue framework that supports generating a static website based on your Vue application. It provides the best of both worlds, as you don't need a server, yet can reap the SEO benefits. Nuxt achives this by pre-rendering all pages and include the necessary HTML. And when you are ready to deploy, Nuxt.js got you covered with simple integrations to serverless and third-party providers such as Netlify, Vercel and GitHub pages.
JungleJS
JungleJS is a free and open-source static site framework for Svelte. JungleJS generates completely static code that doesn't have to be hydrated into a single page application, or SPA.
Plotly
Plotly provides a frontend for data visualization used for machine learning and data science models. With Ploty you can
Express.js
Express.js is a free and open-source web application framework for Node.js, released as free and open-source software under the MIT License. Express is designed for building fast web applications and APIs. In the Node.js community the Express framework is seen as the defacto standard when it comes to building such applications. The philosophy of the framework is to provide a small and robust toolset for building HTTP servers with JavaScript and Node.js. Express does not force you to use any specific database, ORM or templating language, as it leaves that up to you as a developer, to maximize freedom and choice. Express.js is used by companies and hobby developers alike to build single page JavaScript applications, websites, hybrids and public HTTP APIs.
HubPress
HubPress is a free and open-source static site generator written in JavaScript, powered by Vue.js, Asciidoctor and GitHub. All you need to create a static site with HubPress is a free GitHub account, no servers or subscriotion fees. To setup HubPress you simply fork the hubpress.io repository, update the config file and you are ready to start your blog. HubPress uses the free hosting provided by GitHub Pages to achive zero hosting cost.
Reaction Commerce
Reaction Commerce is an open-source, headless, API-first, and modular commerce stack made for ambitious brands and retailers. Reaction’s service-based architecture is built to deliver flexibility and freedom at scale.
GitBook
Semantic UI
Semantic UI is a free and open-source framework for HTML and CSS. The framework treats words and classes as exchangeable concepts. Classes use syntax from natural languages like noun/modifier relationships, word order, and plurality to link concepts intuitively. Semantic UI provides similar benefits to that of BEM or SMACSS style guidelines.
Hexo
A fast, simple & powerful blog framework and static site generator powered by Node.js. With Hexo, you can quicly build static websites and blogs that generates at an increaible speed. Hexo generates hundreds of files per seconds and quickly builds and push your website to deployment, with a single command. You can have your site up and running in minutes on well known hosts and platforms like GitHub Pages, Heroku, Digital Ocean and other platforms. The framework support all features of GitHub Flavored Markdown and most Octopress plugins by default. Hexo is released free and open-source under the MIT License.