Photoshop is one of the most well known names in the editing world for photography, and today Adobe has come out with it's Photoshop CS6 Public Beta! This means you have the ability to download a $1000 application absolutely for FREE! Now for you PC users out there, they also have the beta for you, although the file size is almost doubled, MAC = 984 MB vs PC = 1.7 GB, it's still the same thing. 
To download Photoshop CS6 BETA click here! 