We love the elegant demos and documentation filaraujo is creating for his collection of web components. His akyral-modal component, for example, addresses the common need to have a modal dialog or other UI appear in front of other elements on the page. Several other modal components exist, but none so nicely documented.
Likes: The author's taken care to give akyral-modal a bare-bones appearance. We find often it easier to add our own visual style to a plain component than to try to override a complex visual styling baked into a component's default appearance. We're also a big fan of interactive demos that can be configured on the fly. A demo is worth 10,000 words.