The official Google Docs blog announces features and explains the technology behind the editor, file storage, and Office collaboration support.
HN links it for the new editor's technical write-up, including its JavaScript-based rich text editor, and for product announcements that commenters check for details.
Google originally pioneered Gears as a way to get webapps to work offline (at a time when HTML5 was still being hashed out by WHATWG) and tried to get it adopted as an open standard (http://gearsblog.blogspot.co.uk/2008/04/gears-and-standards.html).
Spreadsheets had (view-only) offline capability via Gears as far back as 2008 (see http://googledocs.blogspot.co.uk/2008/04/view-your-presentations-and.html) but this was then discontinued in favour of the standards methods. FWIW, they have been helping with the HTML5 storage APIs from the beginning.
The HTML5 way of doing offline is AppCache, which Google have used for other products (http://googlecode.blogspot.co.uk/2009/04/gmail-for-mobile-html5-series-using.html) and are presumably using here (or the alternative FileSystem API - http://dev.w3.org/2009/dap/file-system/pub/FileSystem/).
I suspect the Chrome-only limitation is due to the differences in the way is currently implemented, for instance:
* Until Firefox 26's release yesterday, it would prompt for each site that wanted to use AppCache (https://news.ycombinator.com/item?id=6881368).
* Firefox doesn't handle the no-store directive well
* Chrome Apps can be granted unlimited storage (https://developers.google.com/chrome/whitepapers/storage#unlimited)
I came across this old google explanation[1], but I'm not sure it (or this blogpost) are very relevant to today. Google claimed that they kept the image around because it might have been referenced in another site or something, even if the document was deleted, and they appear to still be keeping those old images around, I guess. The claim also seems to be that a cryptographic hash url is as unguessable as a password secured one, though it's not stated directly.
In any case, I actually tried it myself (gasp) with a new doc. Dragged in an image, inspected it to find the URL, deleted the doc, and then permanently deleted the doc again from the trash (I assume it hangs out there for 30 days like with gmail's trash). The image stuck around for maybe 15 minutes, but is now gone, so I don't think this applies to docs today, but I can't find any help document that says either way.
[1] http://googledocs.blogspot.com/2009/03/just-to-clarify.html
Kivo looks a lot like DocVerse. Which was eventually bought by Google and became Google Cloud Connect[1].
Google Cloud Connect was supposedly replaced with Google Drive[2]. No idea if it offers the same functionality. There may be 100,000s of people missing Google Cloud Connect which just isn't enough of a market for Google to pursue.
Personally, I don't think the problem is lack of tools or a better way than email. It's just lack of training or willingness to do something different.
[1]http://googledocs.blogspot.com/2011/02/google-cloud-connect-for-microsoft.html
[2]http://support.google.com/a/bin/answer.py?hl=en&answer=3017040
On the other hand, Google's interns are producing...
http://googledocs.blogspot.com/2009/05/spotlight-on-developers-gadgets-to.html
I know a developer who was learning two new programming languages and started writing serious production code within three weeks of starting his first job post graduation. He took over maintenance of a complex application and rewrote it in a new language. He managed to double his salary 18 months into the job. There risk in hiring someone unproven, but you can buy that down quickly.
The blog post states that if you need more space, you can buy additional storage [<- link to page Aaron linked to] for $0.25 per GB per year.
I'm guessing they simply haven't updated the page to reflect that the storage is shared across Docs as well.
Edit- confirmed in the comments:
The storage page will be updated later today to reflect the addition of Google Docs.
http://googledocs.blogspot.com/2010/01/upload-and-store-your-files-in-cloud.html?showComment=1263315859590#c5642711433468607964
Should probably take into considerations the upgrades to Google Docs that are currently being rolled out (http://googledocs.blogspot.com/2010/04/new-google-docs.html). Wave like real-time collaborative editing, entirely new backed that doesn't depend on browser editing quirks ec. I'm looking forward to them and think they will solve a lot of the annoyances I have had with document editing with Docs.
I say annoyances, because the value of collaborative editing and online sharing outweigh them.