Burp is a network backup and restore program. It uses librsync in order to save network traffic and to save on the amount of space that is used by each backup. It also uses VSS (Volume Shadow Copy Service) to make snapshots when backing up Windows computers.
It is open source free software (where 'free' means both that you do not have to pay for it, and that you have freedom to do what you want with it) released under the AGPLv3 licence. See the FAQ for more information.
Finally, as with the vast majority of open software, Burp comes with absolutely no warranty. You are responsible for testing it and ensuring that it works for you. Please see the FAQ page for more information on this.
The main author of Burp is Graham Keeling.