The content of http://www.w3.org/2010/01/w3c-chairs-bots/ is:

-rw-r--r--  1    1353 Feb  8 17:31 ReadMe.txt
-rw-r-----  1  168866 Jan 21 09:31 chairs-bots.graffle
-rw-r-----  1  126103 Jan 21 09:31 chairs-bots.png
-rw-r-----  1   46074 Jan 21 09:31 chairs-bots.svg
-rw-r-----  1   19885 Jan 21 09:31 image1.png
-rw-r-----  1  205514 Jan 21 09:31 image2.eps

The license that applies is Creative Commons Attribution 3.0 United States:
  http://creativecommons.org/licenses/by/3.0/us/

<a rel="license" href="http://creativecommons.org/licenses/by/3.0/us/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by/3.0/us/88x31.png" /></a><br /><span xmlns:dc="http://purl.org/dc/elements/1.1/" href="http://purl.org/dc/dcmitype/StillImage" property="dc:title" rel="dc:type">W3C bots</span> by <a xmlns:cc="http://creativecommons.org/ns#" href="http://www.la-grange.net/karl/" property="cc:attributionName" rel="cc:attributionURL">Karl Dubost</a> is made available under the terms of the license <a rel="license" href="http://creativecommons.org/licenses/by/3.0/us/">Creative Commons Attribution 3.0 United States</a>

W3C blog entries referring to the W3C Bots:
  http://www.w3.org/QA/2008/10/w3c-chairs-tshirt.html
  http://www.w3.org/QA/2010/02/w3c_chairs_angels

W3C blog entry on the W3C Bots author's blog:
  http://www.la-grange.net/2009/01/31/w3c-bots