EJS

Embedded JavaScript templating (EJS) is a simple templating language that enables generating HTML markup with plain JavaScript. It is designed for Node.js environments and can also run in the browser. EJS templates blend static HTML with injected JavaScript logic to produce dynamic content.

The primary tags are <% %> for executing JavaScript without output, <%= %> for outputting HTML-escaped text, and <%- %> for unescaped output. A literal percent sign can be written with <%%>. Includes are supported via syntax such as <%- include('header') %>, allowing template composition and reuse of partials.

Templates are compiled into JavaScript functions and rendered with a data object, returning a string containing the final HTML. They can be cached to improve performance. EJS integrates easily with Express by setting the view engine and calling res.render('template', data). It supports locals and simple control flow, enabling loops and conditionals directly within the template.

History and ecosystem: EJS was created by TJ Holowaychuk and became a popular choice for Node.js templating due to its minimalism and closeness to plain JavaScript. It is open source and maintained by the community, with wide adoption in various projects. While lightweight, EJS focuses on straightforward templating rather than advanced layout management.

Limitations and alternatives: EJS emphasizes simplicity and may lack some features found in other engines, such as built-in layout systems or advanced helpers. For more structured templating or richer features, developers might choose alternatives like Pug, Handlebars, or Nunjucks depending on the project requirements.