Any Palm OS hardware
Palm OS 3.5
MathLib

POrbit is a physics-based game where you fly a rocket in a planetary system.

Features:
* Visualize orbits, gravity, and rocket engines -- the graphics are simple, but the physics is realistic.
* Design your own planetary systems, and share with friends
* Make your own objective: try to achieve stable orbit, keep going as long as possible, design a system for yourself or others to outwit, or just fly around and see what happens
* The screen automatically zooms in and out as you get closer to and farther from the planets
* You can customize which buttons fire which thrusters (not specific to any particular Palm device)
* Works on both color and monochrome handhelds