bKappa

bKappa is a 2009 experiment in crude but transparent and cross-platform incremental backup. bKappa backups are simple directory trees and lists of files. They are easy to browse and examine and do not use symbolic or hard links. It is crude in the sense that bKappa only tracks files by name, not by content. This means it cannot detect that a file has been renamed and makes full copies of renamed and partially modified files. It generates standalone restore scripts for the POSIX shell and PowerShell. While it saw real use, bKappa isn't tested enough to be your main backup software. If you are looking for that, BorgBackup and restic are good options as of 2024.

Warning! Old 1.x versions of bKappa are insecure. Do not use them. Because backup metadata is serialized with the "pickle" Python module (https://docs.python.org/2.7/library/pickle.html), a malicious backup can take over your machine.