That's because both are Jinja reimplementations (given the name, I expect Swig is a JS version of Twig[0], itself a PHP implementation of Jinja, and originaly started by Armin Ronacher — Jinja's author[1][2])

[0] http://twig.sensiolabs.org

[1] https://github.com/mitsuhiko/twig

[2] http://fabien.potencier.org/article/34/templating-engines-in...

Yes I figured that out. I just don't understand why this has to exist. It's adding nothing noteworthy and very likely not faster either.

By the example of async which initiates value lookups... it can only be slower and promotes the bad habbit of putting too much logic into views.