I hear about rdiff-backup, but I think its two main drawbacks are:

* on the webpage, there is no new release since 2009.

* has no de-duplication.

I was considering moving my 5+ years old rdiff-backup system to any of those new, promising programs:

* obnam [http://liw.fi/obnam/]

* attic [https://pythonhosted.org/Attic/]

They both do automatic de-duplication, old backup deletion and remote encryption.