The programming language known for its use in web development that can run in web browsers is JavaScript. It is a versatile, high-level scripting language that allows developers to create dynamic, interactive web pages. JavaScript enables client-side scripting, meaning it can manipulate HTML and CSS directly in the browser, providing an enhanced user experience. Additionally, with the advent of frameworks and libraries like React, Angular, and Vue.js, JavaScript has become an essential tool for modern web applications.