Wikipedia [L1 ] is an ambitious attempt to collect much of the world's wisdom in a Wiki.
AMG: I just noticed that the Wikipedia page on Duck Typing [L2 ] completely fails to mention Tcl. This needs to change, seeing as how Tcl pretty much wrote the book on duck typing.
PYK 2014-05-28: I sorta thought Python wrote the book on duck typing. I think expanding the presence of Tcl on Wikipedia is a very useful activity, and hope someone finds the time to expand the duck typing article there.