Open Source Backup Software

ByteSync is a powerful open-source tool for remote file comparison and synchronization, designed to transfer only what truly matters: the differences. Whether you're syncing large files, backing up remote folders, or handling extensive sets of small files, ByteSync delivers speed, security, and efficiency—without unnecessary data transfers. Compatible with Windows, macOS, and Linux, ByteSync leverages cloud-based orchestration with end-to-end encryption, eliminating the need for VPNs or firewall configurations. No continuous background syncing, no bloat—just fast, on-demand file synchronization between remote devices.

FileBunker is a Java/SWT based application which allows for backing up local files to one or more GMail accounts. The files are encrypted and compressed for security and efficiency, and can be restored on demand.

A cloud backup solution that employs the "ChaCha20 + Serpent-256 CBC + HMAC-SHA3-512" authenticated encryption scheme for data encryption and ML-KEM-1024 for quantum-resistant key exchange. Check it out at https://plum-cave.netlify.app/ GitHub page: https://github.com/Northstrix/plum-cave

A reliable rsync based backup system, simple to configure, simple to run, simple to restore data

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.

Java backup tool providing file level data deduplication: If a file is stored, it is never stored a second time unless the file's content changes. Instead, a reference to the stored data is created. This holds true even if the file is moved or renamed.

sfvcheck++ checks the hashes in well-formed filenames against an SFV (Simple File Verification) file.