Interesting read. I remember Crypton being announced almost a year ago [0], and for awhile I paid attention the GitHub repo, but it really felt like a dead product. Looking back at the commit history, I'm not so sure why I had this impression, as it seems pretty lively. I'm thinking that perhaps a lot of those commits were not pushed publicly until recently, but in either case it's good to see it active again.
On a bit of a tangent, regarding this post and the requirements (1-5) they posted, I really wish they would hurry up and finally bring this to their backup clients. It's for far too long been a joke in my mind that they promise "100% Private", "Zero-knowledge", "Secure" online backup, sync and sharing with a closed-source client. I went as far as to sign up with them and download the client, only to never install it because I realized I didn't believe a word they said. They promised (again) at the start of this year to open source their client [1]. I have actually followed the issue closely, and just last year one of the founders was admitting on reddit that it simply wasn't a priority. I don't see why not, as it makes their service complete snake oil, and I can't be the only one who refuses to use their service because of it. Anyway, my point is... perhaps from their perspective this was because of point #4 in the post for this submission (Have clear, well documented code).
[0] https://news.ycombinator.com/item?id=5283072
[1] https://spideroak.com/blog/20140110144419-spideroak-to-becom...
Edit: Here [3] is where they prioritize "growth and profit" over providing what they promise. The granularity on the visible submission date is not very informative, but if you look at the posts JSON, you can see the Unix time in the field created_utc. It was the fist of April, so a little less than a year ago.
[3] http://www.reddit.com/r/IAmA/comments/rmp9l/we_are_spideroak...