Open Source Backup Software
Backup is the one tool you hope never to actually use, which is exactly why people discover it failed at the worst possible moment - a restore is the only real test, and a backup that lives entirely in someone else's cloud is a dependency right where you need certainty most. The open source backup software here handles deduplication and encryption on your side, so the copies land in storage you choose and you can verify a restore works without trusting a vendor's word for it.
restic
Fast, secure backup program with deduplication and support for local and cloud storage backends
Duplicati
Free, open-source backup client for encrypted, incremental cloud backups
Kopia
Cross-platform backup and restore tool with encrypted snapshots, deduplication, and CLI plus GUI
BorgBackup
Deduplicating backup software with compression, authenticated encryption, and SSH storage
Velero
Kubernetes backup and migration tool for cluster resources and persistent volumes
Backrest
Web UI and orchestrator for restic backups with snapshot browsing and restore
Vorta
Qt desktop front-end for BorgBackup on macOS and Linux
BackupPC
Open source backup system for storing Linux, Windows, and macOS backups on a server disk
Bareos
Open-source backup software for cross-network data protection, archiving, and recovery