Cross browser testing is a crucial part of the design process of a website. Releasing a website not suitable for certain browsers is always a risk because you could lose a consistent percentage of users that visit your pages. There are many interesting online tools to test how a specific browser renders the code of a webpage such as Adobe Browser Labs or Litmus but their limit is they only generate a screenshot of tested pages so you can’t have a full control of the code.
For cross browser testing I use an useful feature of Dreamweaver called “Browser Compatibility” that helps check HTML/CSS code by providing alerts and suggestions about how to solve eventual issues related to a certain browser. Then before publishing a website I take a look at the final result with IE, Firefox, Chrome and Safari. And you, which tool do you use?