SharpWired is a client for the Wired network which means a BBS-style client that provide chat, news and file transfers through a server protected by encryption. SharpWired has changed hosting to Google Code: http://code.google.com/p/sharpwired/
VNPIS Forum (NTForum) is a Open Source discussion forum or bulletin board system for web sites running ASP.NET. The latest version is ASP.NET v1.1 and v2.0 with a Microsoft SQL Server backend. The full C# sourcecode is available licensed as GPL. You can