IceWarp and Collabora Are Working on LibreOffice Online Document Editing
libreoffice-from-collabora.com
libreoffice-from-collabora.com
LibreOffice is a very important code base and taking it to mobile devices or making it available in a business setting via web sockets as is being done here, can provide some real value and makes it easy to deploy office software.
So it sounds like it's similar to their earlier demos, where the client is "thin" and the bulk of the work is done on the server, as opposed to being a Javascript/HTML/CSS app that runs in the browser.
Reimplementing the whole LibreOffice in JS/CSS/HTML is totally another beast (see https://news.ycombinator.com/item?id=9263233 about WebODF).
Only two people said anything specific. One was about LDAP issues, and the other was about "files missing", which I Googled and it appears to just be a UI issue (the files dont' appear to be actually missing, just not indexed after a rename+sync).
Is there a different thread that you meant to link to that had actual horror stories about OwnCloud?