The 24th International World Wide Web Conference (May 18-22, 2015)

The 24th International World Wide Web Conference will be held May 18-22, 2015 - in Florence, Italy - with a chosen venue of the Fortezza de Basso

http://www2015.wwwconference.org/ 

http://www.www2015.it/conference-overview/

In recent years, the 2014 conference was held in South Korea:

http://www2014.wwwconference.org/

...presentation slides
http://www2014.wwwconference.org/presentation-slides/

...and the 2013 conference was held in Rio de Janeiro, Brazil

http://www2013.org/index.html

videos of the keynotes speeches...
http://www2013.org/salas/segovia-i/

proceedings... 

http://www2013.org/2013/06/21/proceedings-available-online/

tutorial materials...
http://www2013.org/2013/06/21/tutorial-materials-available-online/

http://www2013.org/papers/companion.htm

Some recent threads of discussion related to this InfoQ article series has raised my interest in possibly attending the 2015 conference...
http://www.infoq.com/articles/Web-APIs-From-Start-to-Finish