Riot.js: Minimal MVP Javascript Library

Riot.js masthead from website
From the Riot.js website:

Riot is a standalone library that weighs 1.49kb (0.81kb gzipped) and has only 3 public methods

Despite the tiny size all the building blocks are there: a template engine, router, event library and a strict MVP pattern to keep things organized.
On a finished application the views are automatically updated when the underlying model changes.