From Adobe Systems:
Create distinctive vector artwork for any project. Used by design professionals worldwide, Adobe Illustrator CS6 software provides precision and power with sophisticated drawing tools, expressive natural brushes, a host of time-savers, and integration with Adobe CS Live online services.
I love CS6!! it is really cool.
i also use following wonderful mac tools if you are interested.
to vector image, I will choose Super Vectorizer http://effectmatrix.com/mac-appstore/Super-Vectorizer.htm
to paint on Mac, I prefer to use MyBrushes which can record the painting process and playback http://mybrushes-app.com/MyBrushes-MAC.html