Performing website validation ensures that your website is working without any problems or errors. Having a website that has various errors is risky. That is because browsers will try to repair the error, but since there are different browsers, each of them will do it in a different way. This in turn can result in some serious problems with your site. It is a shame that there is no standard when it comes to browsers. Until there will be more cooperation between the companies that create the most popular browsers, such errors will be especially dangerous. Nonetheless, there are tools which can help you spot such mistakes:
1. A good tool for validating your HTML or XHTML is http://validator.w3.org/
2. For validating your CSS use http://jigsaw.w3.org/css-validator/
3. To make sure your readers do not have problems receiving feeds use http://feedvalidator.org/
One advice that I would like to give you here is to stick to the most popular browsers like Internet Explorer. I know that other browsers might seem to be more suitable to you, but I think that it is still too early to try to be original and have a browser that nobody else has. Most of the people in the world use Internet Explorer anyway, so try to stick with it as well for as long as it is possible.