BorgBackup

BorgBackup (Borg) is a deduplicating backup program. Content-defined chunking splits files into variable-length chunks and stores only chunks it has not seen before, so daily backups add little beyond the actual changes.

All data can be protected client-side with 256-bit authenticated encryption (AES-OCB or chacha20-poly1305), which keeps backups confidential on targets that are not fully trusted. Optional compression supports lz4, zstd, zlib, and lzma, and obfuscation can mask file and chunk sizes against fingerprinting.

Borg stores backups on any remote host reachable over SSH, and archives mount as user-space file systems for browsing and restore. Single-file binaries run on Linux, macOS, FreeBSD, and Windows Subsystem for Linux. The Borg2 branch is in beta and is not meant for production backups.