It tries to read as much data as possible from defective media. Afterwards unreadable sectors are recovered using the previously created error correction code. The maximum error correction capacity is user-selectable.

If you create the error correction code file in time and keep it at a safe place, you have a good chance of recovering the contents of the disc from typical read errors so that you can transfer the complete data onto a new medium.

This looks a lot like the par format to me. The par format is mainly used in the Usenet. Its able to recover bad rar files and thus make a file that consists of many rar´s readable and usable again.

Useful tool, only thing you need to do is create a recovery code before some parts of the Cd or Dvd become unreadable.

Update: DVD Disaster is still in development, the latest version at the time of writing was released in October 2011. The program supports Blu-Ray discs now in addition to CD or DVD discs.

The homepage now offers additional information about the program’s inner workings. One of the issues that users may run into is that using DVD Disaster for error recovery purposes requires them to have additional storage space ready for the recovery information. The developers suggest at least 15% of additional storage, but since it is possible to select a different value this can mean more or less.

It also needs to be noted that DVD Disaster is only effective if error correction data is written before part of the disc becomes unreadable.