Hi, When I use test.py in PyKerberos against an original Mac OS X Server running caldav it seems to works fine. (port 8008 , directory /principals/) However if I run it against the Apache 2 server shipped with OS X Server 10.5 (port 80 or 443 ; directory /some-protected-realm/) and a realm protected with Kerberos it fails miserably, resulting in *** Running HTTP test Second HTTP request did not result in a 2xx response: 401 and a web server error mod_spnego_apple: Cannot get SPNEGO handle from token: -9 binaryTokenLen=595, base64Len=598 So it seems that PyKerberos authenticates fine against the python server behind caldav but NOT against the stock apple spnego module shipped with the server. Is this the expected behavior or a flagrant bug ? This test was prompted by efforts of Tim Olsen who wrote a kerberos authetication extension for mercurial (hg revision control software) to help me use it on a Mac Os X server. Thanks for your opinion and help on this matter Sincerely Paul Windey Prof. of Physics Université Pierre et Marie Curie windey@lpthe.jussieu.fr