Kerberos for Windows NT 4.0

[Aumy]

Hello everybody
Does anybody know if there is a Kerberos implementation for Windows NT?

We have some W2k/W2k3 Servers in our network as ADCs and File/Print-Servers.
Some clients are W2k/XP, but others still run under Win NT 4.0. Is there a
solution (commercial or not) which makes it possible to set up the whole
network Kerberos enabled to get rid of LM/NTLM/NTLMv2?

Help is highly appreciated! Thanks in advance...
Chris