Friesian School
Friesian.com: Immanuel Kant (1724 1804)
This extensive site chronicles modern philosophy and the role of Kant in the movement. Excellent resource.
Other
Massey Univ.: Saying, Showing, Gesturing, and Feeling
This paper by John Shotter examines language development through Wittgenstein and Vygotsky. He contrasts the theories of language development from both of these psychologists.