Spesso sono molto carini..
mi piacerebbe farmi una lista di quelli interattivi e rilasciati in open source, così da migliorare il mio codice vedendo un po come lo scrivono loro in queste piccole applicazioni web.
1) http://www.google.com/doodles/alan-turings-100th-birthday
code: https://code.google.com/p/turing-doodle/
 
2) TAG AUDIO HTML5
http://www.google.com/doodles/robert-moogs-78th-birthday
code: http://www.html5audio.org/2012/05/googles-moog-doodle-falls-back-to-flash.html
 
3) http://www.google.com/logos/lem/
https://code.google.com/p/stanislaw-lem-google-doodle/
http://www.html5rocks.com/en/tutorials/doodles/lem/
 
4) http://www.google.com/doodles/doctor-whos-50th-anniversary
http://stackoverflow.com/questions/20136141/how-to-make-html5-games-like-google-doodles-doctor-who
 
last) CSS3
http://www.google.com/doodles/eadweard-j-muybridges-182nd-birthday
code: http://thecodeplayer.com/walkthrough/google-doodle-animation-in-css3-without-javascript?s=rl
Belli:
 
http://www.google.com/doodles/douglas-adams-61st-birthday
non animati:
http://www.google.com/doodles/112th-birthday-of-jorge-luis-borges