Alcohol 120% is one know name in CD/DVD authoring category. Alcohol 120% is used to mount, create and burn ISO Images as well as bypassing copy protection code from audio and video cds and Dvds. Alcohol 120% supports several formats such as MDF, MDS, NGR etc. however Alcohol 120% is not freeware.
If you are looking for the way to open MDF (Raw disk image) file or convert MDF to ISO then here is better free alternative AnyToISO which works on both Windows as well as Mac OS X.
AnyToISO can convert/Extract following file formats to ISO image.
BIN, BIN, CDI, DEB, DMG, IMG, MDF, NRG, PDI, UIF
Convert MDF to ISO with AnyToIso
Download AnyToISo 2.5 Lite For Windows.