This article is from the CD-Recordable FAQ, by Andy McFadden (firstname.lastname@example.org) with numerous contributions by others.
Platforms supported: Windows (3.1, 95, NT)
See http://www.centered.com/ (shareware)
Second Copy maintains a duplicate of your files on a different system
or removable media. It runs in the background and constantly updates
the backup. Useful for maintaining an archive of a few files; not
meant for full-system backups.