Handlebars

{{name}} for values, {{#if}} and {{#each}} for blocks, {{{rawhtml}}} when you want to bypass escaping. The philosophy is "logic-less": the template should not hold business logic, only presentation.

Templates can be precompiled into JavaScript functions, removing parsing from runtime. It was standard in Ember and in a great many Node backends. Largely displaced by JSX and component frameworks, but it survives in email templates and code generators.