The tiniest dynamic template engine.
This has no sandboxing, it is unsafe for production usage. This is just an example of what you can do with the 'bad' side of javascript.
console.log("Hello, $$name$$. What do?".tmpl({ name: "devoid" }))
>> Hello, devoid. What do?
console.log("The time is $$ new Date() $$".tmpl())
>> The time is Mon Nov 02 2015 16:55:48 GMT-0600 (Central Standard Time)
console.log("7 + 6 * 2 is $$ 7 + 6 * 2 $$".tmpl())
>> 7 + 6 * 2 is 19