Free Software for JavaScript
Mocha.js
A simple, flexible, and feature-rich JavaScript test framework running on Node.js and in the browser, making asynchronous testing simple and fun. With Mocha, you can run tests serially, allowing for flexible and accurate reporting, while mapping uncaught exceptions to the correct test cases.
Mandarine.TS
Mandarine.TS is a free and open-source minimalist, decorator-driven, MVC framework for Deno. Mandarine consists of four different core modules, Core, Security, Data & MVC which brings a compact, SOLID oriented solution for complex applications. All Mandarine projects are released under the MIT License and its growth is dependant on the members in the community.
nest.land
A blockchain-based package registry for Deno. nest.land combines Deno with the Arweave Blockchain to create a decentralized package registry for Deno. With nest.land developers can publish immutable Deno packages that can never be deleted and easily used for any Deno-powered software project.
knex.js
Knex.js is a free and open-source JavaScript query builder for relational databases. The query builder supports Postgres, MSSQL, MySQL, MariaDB, SQLite3, Oracle, and Amazon Redshift and is designed for easy-of-use and portability. Knex.js can be used with both callbacks and promises and supports transactions and connection pooling while providing async flow control, a stream interface, fully featured query and schema builders.
Pakyow
Pakyow is a framework for building modern websites and web apps. Views update in realtime to stay in sync with backend state. This is done using a traditional, backend-driven architecture, which means business logic is written once and stays on the server (write no JavaScript).
Socket.io
Socket.IO is a free and open-source JavaScript library that can be used for building realtime web applications. The library consists of two parts, a server-side library for Node.js and a client-side library that runs in the browser.
Owncast
With Owncast you can host your own streams. Owncast is a free and open-source, self-hosted live video and web chat server for use with existing popular broadcasting software. Owncast includes a web interface to your video with built-in chat that is available once you start the server. The web interface was specifically built to be editable by anybody comfortable tweaking a web page. Allowing streamers to customize the experience for their audience.
Storybook
Storybook is an open source tool for developing UI components in isolation for React, Vue, Angular, and more. It makes building stunning UIs organized and efficient.