Mellow Panda is a collection of LINUX applications for control of radio receivers. It consists of a daemon and specialized clients (dedicated to each receiver model). There are example clients which Uniden Bearcat and Icom radios.
An easy and light carrier phase differential gps code that takes integrated carrier phase measurements from a ground station and a receiver and returns 2-5cm accuracy on relative positioning.
Servo-Trim uses an Atmel ATtiny2313 microcontroller to apply a nonlinear transfer function to standard RC-component signals. Used e.g. between receiver and servo.