GreenSock - GreenSock community forums where questions about GSAP and HTML5/JavaScript animation are answered. Uncommonly kind and welcoming tone.
Animista - Create beautiful CSS animations in your browser
Clippy - CSS Clip-path Maker - Drag and points to generate clip-path CSS
Keyframes.app - A timeline editor for CSS animations
Peeps: 3D Avatar Maker - Peeps is an interactive 3D avatar maker.
CSS Animation Cheat Sheet - Awesome CSS3 plugin for spiffy animations