DiskDoubler is well described [here][1] in the Garden. The present
downloads are earlier versions that work with System 6 as well as Mac
OS 7.

The 1st download (v. 3.7) was released by Salient Software before they sold to Fifth Generation Systems. This upload is a Disk Copy 4.2 image, compressed with [MacZip][2] (use the same to uncompress).

The 2nd download (v. 3.7.5) was also released by Salient Software.

The 3rd download (v. 3.7.6) Swedish by Salient, Disk Copy 4.2 image,
encoded with [Mar][3]

The 4th download (v. 3.7.7) was published by Fifth Generation Systems.

The 5th download (v. 3.7.1) was also released by Salient Software.

The 6th download (v. 3.2) was also released by Salient Software.

Compatibility
Architecture: 68k

  [1]: http://macintoshgarden.org/apps/diskdoubler-40
  [2]: http://macintoshgarden.org/apps/maczip-106
  [3]: http://macintoshgarden.org/apps/mar