dug song and some cohorts of his did a cross-platform, proof of
concept kerberos browser plugin for USENIX and the university of
michigan a couple of years ago.
http://www.monkey.org/~dugsong/krb-www/
hope these small bits prove fresh and relevant
Thanks for the responses, everyone! In turn, CMU has a similar
plugin in production, although only for IE and Netscape so far:
http://andrew2.andrew.cmu.edu/minotaur/