The perfect Backup and Synchronization Tool

ideas tagCC Creative Commons - Photo by Topato/Roadhunter - Flickr Source: http://www.flickr.com/photos/roadhunter/68017710/Envision the “perfect backup and synchronization tool”.
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[*] synchronize and/or backup selected file sets
[*] unlimited revisions (version history)
[*] support central servers and/or decentralized client exchange (“peer to peer”)
[*] support to backup to external drives, including the full file history
[*] work offline and still have a version history
[*] local revision history is automatically distributed to all participating clients
[*] transparent
[list]
[*] automatically monitors/tracks changes and immediately sync in the background
[*] (alternatively, eg. for files that are constantly changing (email database), do scheduled or manual syncs)
[*] if network/other clients are available, sync with them (including file history)
[*] if connected to selected external drives, auto-sync to it
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[*] safe encryption on all clients/servers (both storage and transfers)
[*] of course, only store and transmit incremental updates (deltas)
[*] “traveller mode”:
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[*] web interface to download individual files from any revision
[*] sync complete set of files from a specific date/revision without admin rights
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[*] open source, FREE
[*] platform independent
[*] independently scalable to “unlimited” clients
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To get the idea, compare with [url=http://moblog.wiredwings.com/archives/20080728/Evaluating-Dropbox-and-Syncplicity-A-First-Comparison.html]Dropbox and Syncplicity[/url].
Sounds too good to be true? It does exist (well, sort of) ! [url=http://www.wiredwings.com/wiki/Untitled_Synchronization_and_Backup_Project]See my wiki for details[/url].