+1 for 16B. I think this logo has the most power and it is also original and
distinctive. You can change the colors and still have the same meaning. I
also like the variations for XWiki Office and XWiki Enterprise, it can be
used as an icon and as a small embedded button.
15 the new version, has been modified a little to much in the atlassian logo
direction. It looked better on original version also.
12E. If the font used in writing WIKI would be another it looked better. It
is too mundane for me.
4A looks nice, but from my point is too much toward cartoonish.
In conclusion my vote goes to 16B. Great work and kudos to all the
participants.
Thanks,
Flavius