You may have stricter internal boundaries of what constitutes a "language" than many of us do. Languages are a spectrum and I find there are few hard boundaries

You may have stricter internal boundaries of what constitutes a "language" than many of us do. Languages are a spectrum and I find there are few hard boundaries in practice. Depending on how you define "syntactic sugar" (and I believe it is a much harder thing to define than you may expect) every language is just "syntactic sugar" for some form of machine code. JSX is a language that takes XML-influenced templates embedded in JS files and compiles that to JS files. EJS is a template language that can embed JS snippets and compiles that to JS files (or interprets it at runtime, though the distinction between compilers and interpreters I think is largely irrelevant here). They both have the same general target compiled language, and they both have similar transformations from an original document to a new process. The biggest difference I mentioned is an "inversion" of what people think of as a template language (the template being the "focus" and scripting it being secondary/embedded), but I don't think that disqualifies it as a template language. Subjective feelings of "syntax sugar" or not, JSX is a language intended to write templates in. That's a "template language" by tautology, if not also by definition.