Show a design at multiple browser widths

Pure css responsive slider

See your site at a bunch of mobile resolutions

"Top and left navigations are typical on large screens, but lack of screen real estate on small screens makes for an interesting challenge. As responsive design becomes more popular, it’s worth looking at the various ways of handling navigation for small screen sizes. Mobile web navigation must strike a balance between quick access to a site’s information and unobtrusiveness."

"If you’ve spent any time building responsive websites with fluid grids, you will have encountered the shock of seeing your beautiful portrait layout distort when viewed in landscape mode (or vice-versa.)"

html5 page quickly

Front end design for developers

A semantic grid framework that relies on mixins from less, sass or stylus.

Responsive bootstrap (2.0)

Responsive web design tools

Responsive design toolkit.

A responsive wordpress portfolio (custom). Looks nice.

A responsive web design portfolio

"Dig responsive design?
Hate fluid grids? Try a Frameless grid."

Responsive grid system

A responsive grid

Good looking agency

One man design shop making attractive responsive designs

A responsive no grid layout

Just what I've been looking for. responsive wordpress framework

Responsive web design gallery

Very clever responsive layout with media query in css

Resizable images.