Duplicati
Encrypted, incremental, compressed backups on storage you already have - Amazon S3, Backblaze B2, Google Drive, Azure, OneDrive, Dropbox, MEGA, Storj, WebDAV, SFTP, FTP, SMB, or a plain local disk - is what the MIT-licensed Duplicati has quietly done for years. Its security model is Trust No One: every block is encrypted with AES-256 (or a local GPG instance) before leaving the machine, and the passphrase never travels, so the storage provider holds only ciphertext. The block-based storage engine gives the best of both backup worlds: after one initial full backup, only changed data blocks upload - modify a tiny part of a huge file and only that part transfers - yet every backup version restores like a full backup in a single operation, with no incremental chains to replay. Deduplication and compression keep remote storage growth slow even across years of versions. A web interface manages everything: the built-in scheduler keeps backups current automatically, flexible filters select folders, file types, or custom patterns, retention policies prune old versions, and an integrated updater flags new releases. On compatible object-lock backends, immutable (WORM) storage protects backup data from ransomware that reaches the credentials. Runs on Windows, macOS, and Linux, free even for commercial use.
Kopia
Engineers who have outgrown Duplicati or rsync scripts tend to appreciate Kopia's design: encrypted, compressed, content-deduplicated snapshots in Go, stored in a repository on any storage you control - S3, Google Cloud Storage, Azure Blob, Backblaze B2, SFTP, WebDAV, or a plain filesystem. Encryption is mandatory and end-to-end: every block is encrypted client-side with AES-256-GCM or ChaCha20-Poly1305 using keys derived from your repository password, and even file names never leave the machine in plaintext. Blocks are packed into 20-40 MB blobs with random names, so the storage provider learns nothing about content or structure. Deduplication is automatic and content-based - identical data across files, snapshots, and even multiple machines backing up to the same repository is stored once. Policies govern everything per-directory: compression choice, retention (hourly through annual), scheduling, and ignore rules. Incremental snapshots are point-in-time records you can mount and browse like a filesystem. This deployment runs the Kopia repository server with its web UI, centralizing backups from multiple client machines over an authenticated API - each client connects with the server URL and certificate fingerprint, and users only see their own snapshots. Error correction, high-latency-tolerant caching, and both CLI and GUI round it out.
Immich
With over 110,000 GitHub stars and one of the fastest-growing open-source communities in the self-hosted space, Immich delivers a Google Photos-grade experience entirely on your own hardware. The platform handles automatic background backup from Android and iOS devices, deduplication, and support for RAW formats, LivePhotos, and MotionPhotos. Its machine learning pipeline runs facial recognition and clustering locally on your server, enabling you to group photos by person without sending a single image to the cloud. CLIP-based semantic search lets you find images by describing their content in natural language, while metadata-driven search covers EXIF data, dates, and locations. The web interface built with SvelteKit provides a responsive timeline view, albums, shared albums with configurable permissions, public sharing links with optional passwords and expiry dates, partner sharing for family libraries, and a global map plotting photos by GPS coordinates. Administrative features include multi-user support with per-user storage quotas, OAuth integration, API key management, and a user-defined storage structure for organizing files on disk. The architecture uses PostgreSQL for metadata, Redis with BullMQ for background job queues handling thumbnail generation, video transcoding, and smart search indexing, and exposes over 400 REST API endpoints documented via OpenAPI with auto-generated SDKs for web, mobile, and CLI clients. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. AGPL-3.0 licensed.
ArchiveBox
Backed by 27,700+ GitHub stars and actively developed with the v0.9.x architectural overhaul introducing an event-driven plugin ecosystem, ArchiveBox delivers the open-source self-hosted web archiving platform that preserves websites, bookmarks, social posts, media, source code, and research material in durable formats before link rot, platform shutdowns, and censorship erase them permanently. Feed it URLs one at a time or schedule automated imports from browser history, RSS feeds, Pocket, Pinboard, Instapaper, Wallabag, Shaarli, JSON, CSV, HTML bookmark exports, and browser extension captures. Each snapshot stores redundant copies as original HTML, rendered single-file HTML via SingleFile, full-page PDF, screenshot PNG, WARC archive, article text via Readability, favicons, HTTP headers, media files via yt-dlp, git repository clones, and structured metadata in SQLite. The Docker Compose deployment bundles Chrome, wget, curl, yt-dlp, SingleFile, and Readability parsers with automatic dependency management and isolation. Interact through the self-hosted web UI with search, tagging, and admin controls, the comprehensive CLI for batch operations, the REST API for programmatic access, or the Python API for custom integrations. The new abx-plugins system enables community extractors with per-plugin configuration, while the append-only-log architecture provides resumable crawls and audit trails. S3, B2, and Google Cloud storage backends sync archives to remote storage via rclone. Running on a dedicated VPS on RepoCloud with guaranteed CPU, RAM, and SSD, full root SSH access, and a browser serial console. MIT licensed.