EJS Embedded JavaScript Templates

EJS is a simple templating language and engine that lets developers generate HTML markup with plain JavaScript. Originally created by Matthew Eernisse and maintained by the OpenJS Foundation, it compiles templates into JavaScript functions for blazing fast rendering performance. The syntax uses delimiters where output tags render escaped values, tags output raw unescaped HTML, and hash tags control flow with conditionals, loops, and includes. Key features include template caching for production performance, client-side and server-side rendering support, custom delimiter configuration for projects with conflicting template syntax, template includes for partials and layouts, and filters for transforming data within templates. The engine works seamlessly with Express.js as a view engine, requiring only a single line of configuration to set the view engine and views directory. Error reporting includes line numbers for debugging, and templates can be precompiled for browser distribution. With over 3 million weekly downloads on npm, it remains one of the most popular Node.js template engines alongside Pug and Handlebars. The Apache 2.0 licensed project supports both synchronous and asynchronous rendering, file system abstraction for custom loaders, and options for controlling whitespace handling and debugging output.