Contributing to open-source projects is a great way to learn and improve your programming skills. Here are some open-source JavaScript projects that are relatively beginner-friendly and could be good places to start contributing:

1. FreeCodeCamp (GitHub Repository: github.com/freeCodeCamp/freeCodeCamp): This project is focused on helping people learn to code for free. It includes challenges, certifications, and a large community. Contributions could involve fixing bugs, improving documentation, or adding new coding challenges.

2. Node.js (GitHub Repository: github.com/nodejs/node): If you're interested in server-side JavaScript, Node.js is a popular runtime. You can contribute by improving documentation, fixing bugs, or even working on small features.

3. Hoodie (GitHub Repository: github.com/hoodiehq/hoodie): Hoodie is a framework for building offline-first applications. It's designed to be beginner-friendly and encourages contributions from newcomers.

4. JavaScript30 (GitHub Repository: github.com/wesbos/JavaScript30): This project offers 30 small JavaScript projects that help you practice and improve your skills. Contributions could involve adding new projects, improving existing ones, or fixing issues.

5. React (GitHub Repository: github.com/facebook/react): React is a widely used JavaScript library for building user interfaces. Contributing to its documentation, working on issues labeled as "beginner-friendly," or helping with tests could be a good start.

6. Atom (GitHub Repository: github.com/atom/atom): Atom is a popular text editor developed by GitHub. You can contribute by fixing bugs, improving the user interface, or developing new features.

7. Ghost (GitHub Repository: github.com/TryGhost/Ghost): Ghost is a professional publishing platform. You could contribute by fixing bugs, improving themes, or enhancing the core platform.

8. Vue.js (GitHub Repository: github.com/vuejs/vue): Vue.js is another popular JavaScript framework for building user interfaces. Contributing could involve improving documentation, fixing bugs, or adding new features.

9. P5.js (GitHub Repository: github.com/processing/p5.js): P5.js is a creative coding library that makes coding visuals and animations easier. You could contribute by improving examples, fixing bugs, or helping with documentation.

10. TensorFlow.js (GitHub Repository: github.com/tensorflow/tfjs): If you're interested in machine learning, TensorFlow.js brings machine learning and deep learning to JavaScript. Contributions could involve improving examples, documentation, or fixing issues.

Remember that contributing to open-source projects involves more than just coding. You can contribute by improving documentation, creating tutorials, testing software, designing user interfaces, and more. Before you start contributing, make sure to read the project's contribution guidelines and code of conduct. It's also a good idea to engage with the community through forums, chat rooms, or mailing lists to get a sense of ongoing discussions and priorities.

Here are some less popular javascript open-source projects:

1. Choo (GitHub Repository: github.com/choojs/choo): Choo is a small and focused framework for building user interfaces. It's designed to be simple and could be a great place to contribute if you're interested in front-end development.

2. Feathers (GitHub Repository: github.com/feathersjs/feathers): Feathers is a web framework for building real-time applications. Contributions might involve improving documentation, fixing bugs, or working on plugins.

3. Preact (GitHub Repository: github.com/preactjs/preact): Preact is a fast 3kB alternative to React with the same modern API. You could contribute by improving performance, fixing issues, or enhancing the library.

4. Rambda (GitHub Repository: github.com/ramda/ramda): Rambda is a functional programming library for JavaScript. Contributions could involve adding new functions, improving existing ones, or writing tests.

5. Gatsby Themes (GitHub Repository: github.com/gatsbyjs/themes): Gatsby Themes allow you to package up reusable functionality, like a sidebar or analytics integration, as a theme. Contributing might involve creating or enhancing themes, improving the documentation, or fixing bugs.

6. Smoothie Charts (GitHub Repository: github.com/joewalnes/smoothie): Smoothie Charts is a JavaScript charting library for streaming data. You could contribute by improving chart types, adding new features, or enhancing performance.

7. Vuido (GitHub Repository: github.com/mimecorg/vuido): Vuido allows you to create native desktop applications using Vue.js. Contributions might involve improving cross-platform compatibility, adding new features, or optimizing performance.

8. Greenlet (GitHub Repository: github.com/developit/greenlet): Greenlet is a small utility library for moving an async function into its own thread. You could contribute by improving documentation, optimizing the library, or fixing issues.

9. ECharts (GitHub Repository: github.com/apache/echarts): ECharts is a powerful charting and visualization library. Contributions could involve improving documentation, adding new chart types, or enhancing existing features.

10. Mithril (GitHub Repository: github.com/MithrilJS/mithril.js): Mithril is a lightweight JavaScript framework for building single-page applications. You could contribute by working on performance improvements, fixing bugs, or enhancing the documentation.

Remember that the popularity of a project doesn't necessarily reflect its value or the impact of your contributions. Less popular projects often have smaller, more tight-knit communities where your efforts can have a significant impact. Before you start contributing, make sure to explore the project's repository, issues, and contribution guidelines to get a sense of how you can best contribute.