 Nielsen's 2012 guidelines that web sites for mobile devices be designed separately from their desktop-oriented counterparts has come under fire from Webmonkey's Scott Gilbertson, as well as Josh Clark writing in .net magazine, and Opera's Bruce Lawson, writing in Smashing Magazine, and other technologists and web designers who advocate responsive web design.In an interview with ".net" magazine, Nielsen explained that he wrote his guidelines from a usability perspective, not from the viewpoint of implementation.However, Nielsen appears to have ignored the emerging software technology related to responsive web design, whereby a single body of code, while requiring more painstaking implementation, can be run on devices of various screen sizes, from mobile screens to desktop monitors.