CSShrome
Chrome’s UI made in CSS 3. Impressive. Probably more a proof-of-concept than a freebie, but still worth a look.
CSShrome is a free Coded design resource made by Dribbble user Adem Ilter. As far as I can tell, its license is Unknown.
Helpful hint: Dribbble users are nice. If the license is unknown, it is usually because they forgot to mention it explicitly; not because they were being stingy. Ask nicely and they will probably allow you to use it.
