It is a simple jquery plugin helping design more responsive and adaptive websites and web applications with almost no setup.It adds dynamic classes to the <body> depending on the operating system, browser and resolution.For ideal responsive web design css is just not enough. it chokes at some point, or has cross-browser and cross-platform issues much more than the wonderful jquery framework.
I have tried it with microsoft internet explorer v7 and v8, firefox, google chrome, safari, opera on windows, and also with an android device. works perfectly on all of them. on the android device (samsung galaxy s) handles the orientation change nicely too.