[gcommer]

The best open source alternative I've heard of so far is clearskies (https://github.com/jewel/clearskies). The implementation isn't complete yet, but it started right with a clear, open protocol definition based on standard technologies.

I've been waiting for some free time to write a client myself - go circuit looks very interesting for that!

[jewel]

Thanks for mentioning ClearSkies. I have only mentioned it in a comment thrice on hacker news when it seemed appropriate (and pretty much nowhere else), and it's amazing to see someone else bring it up!

We've been working to get it to a point where it'd be ready for a "Show HN". We finally got connection encryption working last night, so hopefully that will be in a week or two.

[dirkk0]

Oh, I didn't know that - thank you. High upon my list of things to try is also http://www.seafile.com/en/home/.