Disk emulators
Alcohol 52% is emulation software that allows users to play discs without the need for the physical disc.
DAEMON Tools is a virtual cd/dvd-rom emulator that able to emulate all known copy protections.
Virtual CloneDrive works and behaves just like a physical CD/DVD drive, however it exists only virtually.
Gizmo Drive serves for two purposes: virtual CD-ROM drive and encrypted, virtual hard drive creation.