Apple-Rosetta

From official Mac website "New applications bearing the Universal symbol will run natively on both Intel- and PowerPC-based Mac computers. What about the applications you already own? Enter Rosetta. You’ll never see it, you’ll never configure it, you’ll never have to think about it. It’s built into Mac OS X to ensure that most of your existing applications live a long and fruitful life."

What can you do with this software? What is universal software. Apple has all the answer here, for your convenience i am quoting that page "Mac OS X applications that can run natively on both Intel processor- and PowerPC processor-based Macs are called Universal applications. Even if you don't have a Universal version of an application, you can still use it on an Intel processor-based Mac by means of, Rosetta which comes with every Intel-based Mac."

But the problem is forcing a application this is not optimized for intel processor can cause problems. like one that i faced today. i was using a Mac OSX with intel core two duo processor but for a strange reason i can't start any browser - firefox 2 and safari is installed in that Mac, so i was wondering was causing problem, then suddenly i thought may be it's Rosetta. so i
uncheck the box that says open using Rosetta, problem solved. If you are facing same problem try to do that. here is how you can disable Rosetta support.
"Here's how you can force a Universal application to open using Rosetta:

1. Click the application's icon in the Finder, such as Safari's icon.
2. From the Finder File menu, choose Get Info (or press Command-I).
3. Select the checkbox named "Open using Rosetta."(or uncheck if u don't want to)
4. Close the Get Info window."