List of free JavaScript stuff for developerππ½
If you're looking for all programming tools around JavaScript (not just free). Check this page List of JavaScript Programming Tools

Weblab - Machine Learning notebook for Javascript
Weblab lets you write and evaluate Javascript in an interactive notebook. It gives you a great environment to build Machine learning and Data Science applications.
Tag: javascript, machine-learning, data-science
Create, edit and share notebooks, which are interactive programming environments for javascipt.

npm
Online repository for the publishing of open-source Node.js projects
Tag: javascript, package-manager
Unlimited public packages
YepCode
All-in-one platform to connect APIs and services in a serverless environment. It brings all the agility and benefits of NoCode tools, but with all the power of use programming languages
Tag: Saas, PaaS, serverless, API, workflow, devtools, automation, code, productivity, JavaScript
Credit: 1.000 yeps/month Processes: up to 5 by team Integrations: up to 3 by team Time by execution: 5 minutes

Gulp
Gulp is an open source toolkit built on Node.js and npm. It is used for automating and streamlining repetitive tasks in front-end web development.
Tag: javascript, front-end-development

100Devs - leonnoel.com
Train people underrepresented in tech for high growth careers as software engineers.
Tag: HTML, CSS, JavaScript, learning-resource
Free course to learn (or refresh your knowledge of) full-stack development.