Riot.js DOM Bindings is a template engine that provides a simple and flexible way to bind data to DOM elements. It allows developers to create reusable components by defining templates with expressions that can be evaluated and updated dynamically. The library supports various binding types, including simple bindings, each bindings for rendering collections, if bindings for conditional rendering, and tag bindings for mounting custom components. It is designed for developers working with Riot.js and looking to build interactive and data-driven web applications.