Stack is pixel perfect elements designed to help designers and developers craft great Mac OS X Yosemite application designs. Every single layer is scalable and can be easily implemented into your mock ups.

Fontello tool lets you combine icon webfonts for your own project. With fontello you can: * shrink glyph collections, minimizing font size * merge symbols from several fonts into a single file * access large sets of professional-grade open source icons

Bounce.js is a tool for generating tasty CSS3 powered keyframe animations. The JS library for generating dynamic animations is on its way. Simply add a component, choose the preset. And then you can either get a short URL or export to CSS.

Origami is a free toolkit for Quartz Composer—created by the Facebook Design team—that makes interactive design prototyping easy and doesn’t require programming. Most designers today create static mockups to communicate app ideas. But increasingly apps are anything but static, which means as designers we need a better tool for interaction design.