Galen Framework is a layout and functional testing framework that has its own language for describing the layout. The way you test layout using this approach is by declaring a set of elements on the page and rules describing where each element is expected to be. The elements are being tested relatively to each other. This way you can make your tests very flexible and run them on different browsers and even mobile devices in case your website is responsive
It uses Selenium for interacting with elements on page and getting their locations and dimensions. Once it sees that something is wrong – Galen reports the error, makes a screenshot and highlights the misbehaving element on it.
By SauceLabs you can test various platforms and browsers. SauceLabs offers not only cross-browser testing but it gives you a variety of mobile platforms with tablets and phones and with an ability to choose the device orientation. That means you can build a reliable test automation even for your responsive website and make sure it looks great on all mobile and desktop browsers.
In E commerce domain, the Galen frame work plays an important role by automating the whole checkout functionalities along with the layout testing on different browsers and platforms.