Here is a list of 15 popular GitHub repositories that every web developer should be familiar with:

1. Bootstrap

This is a front-end framework that provides a range of pre-designed components and layout options for building responsive, mobile-first websites.

2. React

This is a JavaScript library for building user interfaces, widely used for building single-page applications.

3. Vue.js

This is another popular JavaScript framework for building web applications. It is known for its simplicity and ease of use.

4. Angular

This is a comprehensive JavaScript framework for building web applications, developed and maintained by Google.

5. Node.js

This is a runtime environment for executing JavaScript on the server side, allowing developers to build scalable network applications.

6. Express

This is a popular web framework for Node.js, providing a range of features for building web and mobile applications.

7. Django

This is a high-level Python web framework that encourages rapid development and clean, pragmatic design.

8. Flask

This is a lightweight Python web framework that is easy to get started with and suitable for small-scale web applications.

9. Ruby on Rails

This is a popular web framework for the Ruby programming language, known for its convention over configuration approach.

10. Laravel

This is a PHP web framework that provides a range of tools and features for building modern web applications.

11. ASP.NET

This is a web framework for building web applications and APIs using the .NET framework.

12. Spring

This is a Java-based framework for building enterprise-grade applications and microservices.

13. Hibernate

This is an object-relational mapping (ORM) tool for Java that simplifies the process of interacting with databases in a Java application.

14. Jekyll

This is a static site generator written in Ruby, widely used for building blogs and other simple websites.

15. Gatsby

This is a static site generator built on React, providing a range of tools and plugins for building modern, performance-optimized websites.

That's all folks! Happy New Year 2023! 🎉🎉🎉