DEC 13, 1999 - Swiss Ephemeris is a high precision, long range ephemeris developed by Astrodienst. And it's free, if you're only going to use it for personal (non-commercial) applications - like astrological research, for example. (Programmers developing their own astrology software can license the ephemeris.) Spanning 10,800 years (5400 BCE to 5400 CE), with documented claims of accuracy to within a few arc-seconds throughout that range - except in the case of the Moon, which can be off a bit more than 12 arc-seconds in the worst case - Swiss Ephemeris is arguably the finest tool for astrological calculation available anywhere today. (Even higher precision is available for most of the years covered.) There are plenty of extras too: including the solar system barycenter, hypothetical planets, over 8,000 asteroids and more. To put all this free power to work generating planetary data for your own research, you'll want to download not only the ephemeris files, but also your choice of demo programs (swewin.exe for Windows and/or swetest.exe for MSDOS). What the heck, they're free, get 'em both. (Personally, I find swetest.exe more versatile, although clumsier to use until you master its cryptic command-line syntax.) Make no mistake, Swiss Ephemeris is not - nor is it intended to be - a chart calculation program. Using the free demo programs and ephemeris files, it will generate accurate celestial positions for just about any date you could reasonably want to work with. What you do with that data - whether to hand-draw a chart, or for long-range research into cosmic cycles - is up to you.
Technical note: Web Site Garage rates Swiss Ephemeris excellent over-all and in load time (8.97 seconds on a 28.8k modem). In comparison, the page you're now reading rates good in both categories (with a load time of 11.05 seconds at 28.8k).
