MarkApp: Building apps with HTML. Widgets and libraries that can be used without writing any JavaScript.
You Might Not Need JavaScript. Various widgets and libraries that are HTML/CSS only.
Hint.css: Pure CSS-only tooltip library
Highlight styles
Lorem Ipsum e-mail: background-color: gold, which is the same as Gary Johnson's e-mail campaign: #FFD700
Animations
Animista: Wizard that lets you browse and create keyframe-based animations
