Planet's Orbits 

Planet's Orbits (for Windows 98/ME/2000/XP) is an accurate digital orrery with a wealth of functionality. The program uses the DE404 ephemeris (accurate for dates between 2000 B.C. and 6000 AD) for the calculation of planetary (except Pluto).
orrery planets asteroids planetary positions solar system astronomy satellites ephemeris

Alcyone Ephemeris 

Alcyone Ephemeris is an accurate and fast astronomial ephemeris calculator covering the period 3000 BC to AD 3500. It calculates heliocentric, geocentric, and topocentric positions of the Sun (Earth), Moon, and planets.
ephemeris ephemerides astronomy planetary positions celestial mechamics