I'm really confused..

I'm looking into making a commercial program and there are a few open source, GPL covered components i'd like to use..

Am I allowed to sell my product with the components in without distributing my source?

For example.. say i was making a commecial text editor, and my friend has a really awesome GPL free-software text editor..

But i wanted to make a text editor like his but with special features..

Am I allowed to fork his text editor add all my special features and sell it on without having the source code to my special features available to my users?