Fluorescent Multilayer Disc
Fluorescent multilayer technology, which can be used in cards or discs, aims a laser at fluorescent recording material, causing it to emit light. Since it doesn't depend on reflected laser light, it's possible to create many data layers (C3D has prototyped 50 layers in its lab). It can use the same 650 nm laser as DVD, so FMD drives could be made to read DVDs. In June 2000, C3D announced a program to make FMDs with 25 GB per side that would be readable by DVD drives with a "minor and inexpensive modification."
FMD is a new technology, with no track record, supported by one small company. DVD is based on decades of optical storage technology development by dozens of companies. It's possible that FMD could become established in few years, but DVD is already so entrenched that FMD drives will have to read DVDs in order to succeed. So there is little worry of DVD becoming obsolete any time soon. Perhaps FMD will be the third generation of the DVD format, following the high-density blue-laser version currently under development