The SimulAVR program is a simulator for the Atmel AVR family of microcontrollers (ATtiny and ATmega). SimulAVR can be used either standalone or as a remote target for avr-gdb. There are interfaces for Python and Tcl. When used in gdbserver mode, the simulator is used as a back-end so that avr-gdb can be used as a source level debugger for AVR programs.
OpenSCB is a hardware and software solution for controlling servos over USB. The hardware is designed to interface with classic RC servos, AX-12/AX-18 servos, OpenServo, and more using a powerful 32-bit microcontroller with a USB port for programming and control with a PC. The schematic and layout will be available and can be customized. A graphical interface is also provided for your computer to configure, calibrate, and control the board.