Duplicati is the only portable backup program, able to send backups in encrypted form to another computer or SkyDrive using one of several methods (WebDAV, FTP, SFTP/SCP/SSH, Amazon S3, Rackspace CloudFiles, USB disk, Windows network share). Time scheduler e.g. for auto-backups every 3rd Monday on 10 a.m.
German, Danish, English, French, Portugese. Can also be startet from command-line. Support for snapshots via VSS and LVM: Backup of open files.
Duplicati is a rewrite of Duplicity/ftplicity, written for Windows (in managed C# .NET). It also runs on Linux using the Mono framework.
The initial backup is sent in encrypted format, and afterward, only changed files (diffs) are sent (also in encrypted format). This allows one to save space and bandwidth.