Firefox has been getting a set of very interesting tools for developers. Already, the tools available are quite useful, though not as comprehensive as the ones in Chrome, but Mozilla is not stopping. The latest Firefox 15 beta comes with plenty of improvements and some new tools as well.
Also new in Firefox 15 is the "layout view." This simple tool is very, very useful when designing a website or an app. It reveals all the useful measurements of any selected element, i.e. its internal and external width and height along with padding, margins and borders.
Firefox 15 also adds the "Responsive Design View," essentially the ability to view a web page inside a resizable window, so you can see how the design fares with smaller windows and various aspect ratios. It’s especially useful for those targeting or at least thinking about mobile devices.
Firefox now comes with a High Precision Event Timer, which is part of the Performance API, making it possible to get very precise time measurements, in the milliseconds, useful for apps or games in particular.
Finally, WebGL is getting some love as well, several more advanced techniques and features have been added. "Firefox Beta adds support for compressed textures, enabling significant performance gains for WebGL applications. In addition, WebGL is available on Firefox for Android in as an experimental feature. Expect more to come in future releases," Mozilla explained.