SVG.JS is a lightweight library for manipulating and animating SVG. With it, you can create masked headers like the one at the top of this page. With svg.js, you have all the power of vector graphics at pocket size. The whole library is about 11k gzipped. Its features are:

– Easy readable uncluttered syntax

– Animations on size, position, transformations, color, etc

– Painless extension thanks to the modular structure

– Various useful plugins available

– Unified API between shape types with move, size, center, etc

– Binding events to elements

– Full support for opacity masks and clipping paths

– Text paths are even animated

– Element groups and sets

– Dynamic gradients

– Fully documented