Janus.Net 1.1 experimental — version 1.1.1569.19993 — contains experimental code to perform HTTP Basic and NTLMv2 authentication to HTTP based proxies. The only reliance on library code by the NTLM support is for the System.Security.Crypto.MD5 class — everything else for NTLM is in-line. The code is experimental in that I've tested the authentication code against a local copy of IIS, rather than against a real authenticating web proxy.
From the Windows page.