The syntax of m4 is unwieldy, a "standard library" would be also needed to make it useful for smaller tasks. How often do you define loops yourself? Sadly this

The syntax of m4 is unwieldy, a "standard library" would be also needed to make it useful for smaller tasks. How often do you define loops yourself? Sadly this holds to an unexpected degree for Mustache. [1] - looks like a DOM AST + Javascript to me, quite unlike template