Escodegen is a JavaScript code generator from an abstract syntax tree (AST). It's commonly used in tooling for code transformation, minification, and analysis. It accepts an AST, compliant with the Mozilla Parser API (SpiderMonkey), and generates readable, well-formatted JavaScript code. Escodegen supports various output formatting options, including indentation, semicolons, and line breaks, allowing fine-grained control over the generated code's style and readability, aiding in tasks like debugging or modifying existing JavaScript programs.