eslint-plugin-es5 helps maintain ES5 compatibility in your JavaScript code. It flags code that uses ES6+ features unsupported in older environments, such as Internet Explorer or older Node.js versions. Using this plugin allows developers to write modern JavaScript while ensuring their code remains functional in legacy browsers and systems. Configure rules to fit specific support targets, preventing accidental use of newer syntax, methods, and APIs. Enhance code stability and avoid runtime errors caused by browser incompatibility.