UDPonTCPproxy proxies UDP traffic from a set of ports over TCP tunnels. Server side NAT's the UDP ports to a chosen destination, then sends back destination's replies. Usefull to tunnel UDP over SSH tunnels to things like license or game servers.
LANdialler allows workstations (Windows, Linux, etc.) on a LAN to control and share a modem attached to a Linux server. It is designed to be used with PPP and NAT on a Linux router to provide a home or small office with shared Internet access.