When it comes to programs that can mount ISO images to a virtual drive, without having to burn them to a CD, Daemon Tools instantly springs to mind. With the features that this program brings, it’s hard to for a newcomer to make any place. However, OSFMount comes with an unique feature.
OSFMount is a program that can be used to mount disc images as virtual drives, but also supports RAM disks (a disk mounted into RAM), which is the unique feature among the competitors. This means that you can get the fastest access to disc images and the best overall performance of the mounted images.