Topcoat is a brand new open source CSS library designed to help developers build web apps with an emphasis on speed. It evolved from the Adobe design language developed for Brackets, Edge Reflow, and feedback from the PhoneGap app developer community.
We’re actively working on it to make it even more awesome with fresh releases every month. Our biggest goal is to start building a community around Topcoat and we’re structuring the project so that contribution is easy.
You can download the free PSDs on Github here:

Icons are available for download here:
Dark theme
Light theme
Custom theme
Desktop components
Open source icon set