Capybara is an open-source acceptance testing framework for web applications, designed to simulate how users interact with a web application. It allows developers to write tests in a natural language style, making it easier to understand and maintain. Capybara supports various drivers for different browsers, enabling comprehensive testing across multiple environments. The framework integrates seamlessly with popular testing libraries like RSpec and Cucumber, facilitating behavior-driven development (BDD) practices. Capybara is widely used in the Ruby community and is recognized for its ability to enhance the reliability and efficiency of web application testing.