BackupPC is a free disk-to-disk backup software suite with a web-based frontend. The cross-platform server will run on any Linux, Solaris, or UNIX-based server. No client is necessary, as the server is itself a client for several protocols that are handled by other services native to the client OS.
License: Open Source
CrashPlan is a user-friendly, subscription-based cloud backup solution with strong encryption and real-time syncing, making it ideal for users seeking ease of use and security. In contrast, BackupPC is an open-source, highly configurable backup tool that is best suited for users with technical expertise who require flexibility and control over their backup processes.