Open Source Software for JavaScript
RethinkDB
RethinkDB is a scalable, open-source database designed for real-time applications. When your app polls your database for data, it becomes slow, unscalable, and cumbersome to maintain. RethinkDB solves this by providing a new database access model, where developers can instruct the database to continuously push updated query results to their applications, without polling.
RedwoodJS
RedwoodJS is a free and open-source fullstack JavaScript framework for the JAM stack. The framework is highly opinionated and utilize the best practises for building fullstack web applications with React, GraphQL, Prisma and relational databases. Redwood is designed to be deployable completely to the Edge via CDNs and serverless functions distributed everywhere. The structure and tools provided by RedwoodJS let's you get up and running quickly, so that you can see your application go from idea to reality.
Formik
Formik is a free and open-source library for building forms with React. The library improves on the otherwise verbose process of creating forms in React by minimizing the need for repetition and eliminating the cumbersome process of keeping track of values, errors, visited fields and orchestrating validation and error handling.
Matrix.org
Matrix.org is an open network for secure, decentralized communication. It gives you a simple HTTP APIs and SDKs (iOS, Android, Web) to create chatrooms, direct chats and chat bots, complete with end-to-end encryption, file transfer, synchronised conversation history, formatted messages, read receipts and more. All conversations on Matrix are replicated over all the servers participating in them, meaning there are no single point of control or failure.
HumHub
HumHub is a free and open-source social network software and framework built to give you the tools to make communication and collaboration easy and successful. HumHub is designed to be lightweight, powerful and comes with an user-friendly interface that is easy to use both for users of the social network and administrators.
VuePress
VuePress is a free and open-source Vue-powered Static Site Generator or SSG for short. VuePress utilize the power and simplicity of Markdown files to generate content. Which allow the creator to focus on their writing, instead of formatting HTML. With VuePress, developers can harnes the power of Vue components in a simplified build step using Vue + webpack.
Sails.js
Sails.js is a JavaScript framework that makes it easy to build custom, enterprise-grade Node.js apps. It is designed to resemble the MVC architecture from frameworks like Ruby on Rails, but with support for the more modern, data-oriented style of web app development. The framework is suited for building applications with realtime features.
Plenti
Are you tiered of the complexity when it comes to setting up a website? A static site generator like Plenti might be your solution. Plenti is a static site generator written in Go for speed and utilize Svelte for ease of use on the frontend. With Plenti, you can ditch the headaces of maintaing a content management system and SQL databases. Plenti simply connects to your Git backend and be pushed to production using GitHub Action or Gitlab Pipelines.
ct.js
ct.js is a 2D game editor that makes learning programming fun and game development easy by its visual tools, good docs and flexible, modular library. ct.js is based on Pixi.js, works on WebGL and provides great performance in browsers and desktop environments. The game editor is extensible through the use of Modules which adds new powers when ct.js core is not enough. Hobyist and professionals alike use ct.js to create 2D shooter, arcade, adventure, survival and puzzle games.