Cardinal is a small and mobile-first CSS framework that positions itself as a starter-kit, provides the basics and lets the users customize/develop the rest.
Skel.js is a tiny JavaScript framework what have a 12-column grid system (~6kb gzipped and minified) that simplifies building responsive layouts very much.
iLightBox is a fresh alternative to other jQuery lightbox plugins and there is a strong chance that, although it is a paid resource,В it may become your favorite.
Using responsive CSS frameworks developers can speed up the delivery and improve the quality of responsive CSS code. Since responsive web design is in high demand a lot of frameworks have been created to streamline the delivery of high quality mobile-ready websites.