As a user of the "prototype.js" library this is a little similar to the default template syntax, yet with one extra character.

Thomas Fuchs has a very similar version: http://mir.aculo.us/2011/03/09/little-helpers-a-tweet-sized-...

And finally, I ported the template functionality from the "prototype.js" to php. https://github.com/freshteapot/php-template

Prototypejs - api of "Template" http://api.prototypejs.org/language/Template/