JerryScript is comprised of two main components: Parser and Virtual Machine (VM), with the parser performing translation of input ECMAScript application into byte-code than is then executed by the Virtual Machine that performs interpretation.
Although JerryScript is designed for MCUs, and is said to be running on hundreds of thousands of smartwatches, you can easily build it and try in any machine running Linux:
git clone https://github.com/Samsung/jerryscript.git
jerry> print ('Hello, World!');