MultiVNC is a cross-platform, Multicast-enabled VNC viewer. Features include support for most encodings, ZeroConf service discovery, a seamless edge control mode á la x2vnc, and most prominently, experimental support for VNC via multicast.
RemoteViewing is an embeddable .NET-native VNC client and server library.
It supports Raw, Hextile, Copyrect, and Zlib encodings, and includes a Windows Forms control to make embedding VNC in your program extremely easy.