You see, the nature of CSS runs contrary to don’t repeat yourself ( DRY) principle that is exhibited in good software engineering.
So far this tool has proven quite useful by showing what happens when developers try to make use of CSS selector syntax that may not be supported in a particular browser. Specifically, it can show how and perhaps why a particular CSS hack works in some browsers and how it is ignored in others. It can also demonstrate the potential for harm when using unsupported CSS syntax in some browsers. For instance, when testing a combined selector “.class1.class2” in Internet Explorer 6, it becomes active as “.class2”, which may not at all be the goal of the CSS author.
Another detail the CSS Selector Shell demonstrates is that shorthand property/values sometimes expand much further than you may have suspected. On the test page itself, there are two visible test elements that you can use to target and experiment.
I hope this tool will be useful to you in diagnosing problems or understanding the differences between browsers when interacting with your Cascading Style Sheets.
For open source contributors, I think Appchin.com is one of the greatest places for having impact. By taking on challenging tasks, you can make changes that affect millions of users. Nothing is more exciting than seeing your code change the world.