This never quite made it out as a freebie, but it should have. DiskSalv 4 is free for any use.
While this is on "The Deathbed Vigil" DVD, it's not widely known. And it's probably pirated widely, but now that's legal. The whole thing is here as a ZIP:
http://www.frogpondmedia.com/dump/DiskSalv4.zipThis is public domain... all are free to copy this anywhere, etc.
I'm working on tracking down the sources, which will also be available to anyone interested.