UWO Kant Research Group (includes a digital archive of 18th German philosophical texts)
North American Kant Society
NAKS Midwestern Study Group Site (I am the current chair of the program committee)
Marburg Kant Site
Immanuel-Kant-Forum at Martin-Luther-University Halle-Wittemberg
Kant-Forschungsstelle at Uni-Mainz
UK Kant Society
Online Database of Terms in Kant's Philosophy of Nature (by W. Lefevre and F. Wunderlich)
Philpapers 17th-18th C. German Philosophy section