HTML5 editor

Looks great !
Way better than TinyMCE or FCKEditor ! But much more immature and less features.
in reference to: Aloha Editor - The HTML5 Editor (view on Google Sidewiki)

DocBook collaborative Editing Web Platform

Really great. Still alpha stage at this point, depending on the browser, but very promising !
Maybe looks a bit complicated, but since it is Open Source, it will be possible to simplify and modularize it.
I am watching with great attention !

in reference to:

"collaborative Editing Web Platform"
- Calenco XML CMS (view on Google Sidewiki)

WikBook, Wiki 2 Docbook java translator

Nice to see that there are still ongoing efforts to produce Docbook. But:
- Currently only produce "Book" this may be overkill for document < 20 pages, where an "article" is lighter.
- You have to install the tool (I need a web site ala SaaS)
- You need to run the translator and then the docbook tool chain to finally open the resulting html or pdf file and see the result
- no annotation support

in reference to: wikbook - Project Hosting on Google Code (view on Google Sidewiki)

Structured editor

I am still searching a structured editor. A WYSIsWYM (What You See Is What You Mean) kind of editor.

At this stage, I am very disappointed with the new Google Doc. They could have done something well structured with HTML, but their new markup is just format oriented. A lot of span containing inline style. Unusable. (Same with Zoho and ThinkFree.)

The best structured editor I could find is Syntext Serna: Open Source, Free, multi-platform, supports XHTML, DocBook, DITA and more! 

I tried a lot of other tools:

• Amaya : the usability is far below Syntext Serna. Maybe an option if you are in XHTML, MathML, SVG trip. But it doesn't seem to support even HTML 5. 
• Lyx: again the usability is not there. It is way too complex. Only an option if you are in the  TeX/LaTeX trip.
• XML Copy Editor: Maybe in ten years ...
• Gwennel: FreeWare WYSIWYG and WYSIWYM editor for Windows only, supporting natively the Open Document Format.
• Conglomerate "XML editor that everyone can use. In particular, our primary goal is to create the ultimate editor for DocBook and similar formats". (GTK ; Died in 2005)
• DocBook Wiki "display DocBook documents online. Different from the other applications, which convert a DocBook document into HTML first, in order to display it online, DocBookWiki converts it on the fly, so that the format for saving the document will still be XML". (Died in 2005 too)
• There is also XML Mind : it is a very good structured editor, but it has too many restrictions: non Open Source, free only for non-commercial use.
• I admit that sometime I just use MS-Word in outline view :-) If interested, there are also commercials: ArborText, FrameMaker ...

More recently I searched for online structured editor. Google Doc is out, I tried Zoho and ThinkFree without luck.

I also searched Chrome Extensions:

• ScribeFire: nice for blog, but not structured.
• Chrome Editor: a bit strange. I have to investigate more.
• PageEdit it uses CKEditor, it might be configured to produce structured HTML. I have to investigate more.
• iDoc: too simple and lack usability.