Pmount - Pmount is software that allows you to mount storage devices or drives into Windows and use them as a normal storage device.
Usbmount - Usbmount is a software that allows you to mount USB storage devices as you plug them and are unmounted after unplugging.
Udevil - Udevil is software that lets you mount a storage device and create a utility to control it with a ton of optimization options.
Gmount ISO - Gmount ISO is a lightweight solution that is mainly used for instant mounting and dismounting ISO images.
eMount - eMount | Mount, encrypt and manage disk image files and physical disk drives.
WinCDEmu - WinCDEmu is an open-source CD/DVD/BD emulator.