Alcohol 120% is an optical disc authoring program and disk image emulator created by Alcohol Soft. Alcohol 120% began as a direct continuation of the defunct Fantom CD CD-ROM drive emulation software. Alcohol 120% can create disk images, either in its proprietary Media Descriptor Image file format, or in a number of other popular formats (listed below). The second popular feature of the program is its capability to emulate up to 31 virtual drives to mount disk images, making it unnecessary to have a physical copy of the disc. Virtual drives can operate at over 200 times the speed of the conventional CD-ROM drive. Alcohol 120% can also be used to burn these images (as well as those created by other software) back onto CDs and DVDs. It supports simultaneous writing to multiple CD/DVD writers.