Remote Desktop server/client (proprietary protocol) (written in java)
jVNCLite is a Java VNC server/client. Uses it's own proprietary protocol (not RFB). Server uses JNI and requires Microsoft Windows system. Client is 100% java. Only one problem left with some multi-monitor systems.
TightVNC is an improved version of VNC, great free remote-desktop tool. The improvements include bandwidth-friendly "Tight" encoding, file transfers in the Windows version, enhanced GUI, many bugfixes, and more.