As ganzey said, he's referring to ISO/DMG images. For Windows I'm partial to WinRAR, which lets you view the contents of the image and extract parts or all of the data. Mac already had that built in.What do you mean "process"? Personally, I like Picasa. It's great to navigate through many images, and it can be used to make small adjustments to images very quickly. I like it because it allows me to adjust brightness/contrast and crop my images for eBay very efficiently. I can go through dozens of images in just a few minutes.