[SkyMarshal]

Anyone using SpiderOak? They're the only other versioning diff-based backup service I know of that supports Linux (with a free tier; there's also Tarsnap). They also claim 'zero-knowledge' encryption. Anyone have any opinions?

[tincansandtwine]

There's also ownCloud (http://owncloud.org/index.php/Main_Page), if you're into that whole home server thing. It definitely supports Linux.

[eropple]

It supports Linux poorly, and supports nothing else at all.

(WebDAV isn't "support," when you look at the Dropbox/SpiderOak feature set.)