OSFMount allows you to mount local disk image files (bit-for-bit copies of a disk partition) in Windows with a drive letter.
OSFMount also supports the creation of RAM disks, basically a disk mounted into RAM. This generally has a large speed benefit over using a hard disk. As such this is useful with applications requiring high speed disk access, such a database applications, games (such as game cache files) and browsers (cache files). A second benefit is security, as the disk contents are not stored on a physical hard disk (but rather in RAM) and on system shutdown the disk contents are not persistent.
OSFMount supports mounting images of CDs, which can be useful when a particular CD is used often and the speed of access is important.
Free software to mount disk images with a drive letter in various format. As a bonus it also does RAM drives.
I was trying to recover a deleted video from a friend's memory card. I used Roadkil to create an image. But no program seemed to be able to mount the resulting IMG file... Until I tried OSFMount!I used PhotoRec on the resulting mounted IMG and got her video back. Yay!