‘S3QL is a file system that stores all its data online. It supports Amazon S3 as well as arbitrary SFTP servers and effectively provides you with a hard disk of dynamic, infinite capacity that can be accessed from any computer with internet access.’

‘ddar is an open source userspace de-duplicating archiver for Unix.’

‘Simple version control and backup for photos, videos and other binary files.’

A DropBox-alike using Ruby and Git.

‘omnisync is a universal file synchroniser and backup program (think rsync) that supports multiple transport systems (such as plain files, sftp, s3 and virtual, currently, and support for ftp, http, et al is planned).’

‘I love adapting programmers' tools for my writing. They tend to be extremely well-made and stable (because if they aren't, programmers will fix them or find better ones) -- it's like using chefs' knives in the kitchen.’

I'm now doing this: even if my Google Code repository goes dark, I still have my data.

A write-once system using hashes of data blocks to identify them.