XXtl

XXtl is a templating language designed to transform structured data into human-readable text. It aims for a small, composable core that supports data-driven rendering, enabling templates to adapt to varying input without hardcoded structure.

The name XXtl appears in educational materials and prototype projects as a generic example of a template language. There is no single official standard, and implementations vary across languages and communities. In discussions, XXtl is often compared with other templating systems such as XSLT, Mustache, and Liquid to illustrate differences in data access, control flow, and extensibility.

Core features typically include data-path expressions to reach values in nested structures, conditional rendering, loops over arrays or lists, and support for defining reusable templates or fragments. Many designs also allow importing or composing templates, and some provide user-defined functions to transform data during rendering. Execution can be performed at runtime or precompiled to an intermediate form.

Although XXtl syntax differs by implementation, templates generally interleave static text with interpolated expressions. A trivial example might render a name field from input data, as in Hello, {{ name }}. More complex templates can iterate over a list and format each item.

XXtl remains primarily a pedagogical or research-oriented concept rather than a widely adopted production standard, used to demonstrate template language tradeoffs and to teach data-driven rendering. It informs discussions of readability, performance, and extensibility in templating languages.