The most popular nowadays library for building Web applications with awesome configuration possibilities and maintainability. Have one of the biggest communities and tons of real-applications examples.
The real juicy part is the reference section. All hooks, components and API definitions, examples, practice problems are given in a self learning way. This documentation is fun to read.
You can't get wrong with React. The only UI library I have ever worked with. And I have no intention of switching it with another one. Two thumbs up for the React community.
