Proxmox Backup is a stand-alone solution. The open-source nature of the Proxmox software stack means that you get a secure, flexible product that you can trust. The source code is free and open-source, licensed under the GNU Affero General Public License, v3 (GNU AGPLv3). Thus, you are free to use the software, inspect the source code at any time, or contribute to the project yourself.

The whole Proxmox Backup software stack is written in Rust, a modern, fast, and memory-efficient language. Rust provides high speed and memory efficiency, due in part to its lack of runtime and garbage collector. Its rich type system and ownership model guarantee memory-safety and thread-safety.

Backups are sent incrementally from the client to the Proxmox Backup Server, where data is then deduplicated. Typically, changes between periodic backups are low. Reading and sending only the changes reduces the storage space used and the network impact.

Periodic backups usually produce large amounts of duplicate data. The deduplication layer in the Proxmox Backup solution reduces the amount of duplicate data, reducing the physical space required for data storage.