is zac efron dating vanessa hudgens or ashley tisdale - The times dating website
It is a front end to duplicity that performs incremental backups, where only changes since the prior backup was made are stored.
Note that as of February 2016 this project appears to be almost completely ignoring bug reports with only minor triage activity and the last bugfix dates back to 2014, though there are new releases with minor changes. You can't restore specific versions of individual files very easily.
However you can restore the entire backed up content to a specific backup.
For instance I can restore to last week, or to the week before, or the week before that, etc It can connect to anything nautilus can see.
This question exists because it has historical significance, but it is not considered a good, on-topic question for this site, so please do not use it as evidence that you can ask similar questions here.
While you are encouraged to help maintain its answers, please understand that "big list" questions are not generally allowed on Ask Ubuntu and will be closed per the help center.
I would say the backup solution depends on what you are using the machine you are backing up for.
A collection of work/school critical projects/code has a far different set of needs from a computer storing an ungodly amount of porn and music.
On my home setup I have a small script that backs up a couple of folders I wouldn't like to lose, it does this incrementally.
My work laptop gets everything backed up to a server and never has mission critical stuff left on it anyway.