Astrolog is an open-source astrological software program that has been available online free of charge since 1991. It has been (as of 2022) authored by Walter Pullen since its creation, and was originally distributed via postings to the

Usenet Usenet () is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Ellis conceived the idea in 1979, and it wa ...

newsgroup . Astrolog can create horoscopes,

natal chart A horoscope (or other commonly used names for the horoscope in English include natal chart, astrological chart, astro-chart, celestial map, sky-map, star-chart, cosmogram, vitasphere, radical chart, radix, chart wheel or simply chart) is an ast ...

s, and calculate current planetary positions in sidereal, traditional, and heliocentric formats. It can be used to relate astrological house and sign dispositors and other nonstandard systems. Astrolog uses 23 different house systems, can calculate 24 different aspects such as trines, squares, semisquares, and rarer ones such as biquintiles, quatronoviles, and sesquiquadrates. Astrolog computes the traditional planets, along with asteroids such as Ceres, Juno and Vesta,

trans-Neptunian object A trans-Neptunian object (TNO), also written transneptunian object, is any minor planet in the Solar System that orbits the Sun at a greater average distance than Neptune, which has a semi-major axis of 30.1 astronomical units (au). Typically ...

s such as Eris, Haumea and Makemake,

uranian object Alfred Witte (2 March 1878 in Hamburg, Germany – 4 August 1941 in Hamburg, Germany), was a German surveyor, astrologer, an amateur astronomer, and the founder of the Hamburg School of Astrology. Witte revived and further developed the use of ast ...

s such as Vulkanus and Russian Proserpina, and 27 different planetary moons. It can show nearly 50 fixed stars, and animate the chart in real time synchronized with the OS clock. Astrolog can do forms of locational astrology such as

astrocartography Astrocartography (called "astrogeography" in Europe in earlier years) is a method of locational astrology, by which specific geographic locations are associated with expected differences in personal life circumstances. Technique Developed and pop ...

. Recent versions use the

tz database The tz database is a collaborative compilation of information about the world's time zones, primarily intended for use with computer programs and operating systems. Paul Eggert is its current editor and maintainer, with the organizational backi ...

for

time zone A time zone is an area which observes a uniform standard time for legal, commercial and social purposes. Time zones tend to follow the boundaries between countries and their subdivisions instead of strictly following longitude, because it ...

and

daylight saving time Daylight saving time (DST), also referred to as daylight savings time or simply daylight time (United States, Canada, and Australia), and summer time (United Kingdom, European Union, and others), is the practice of advancing clocks (typicall ...

detection. All versions of Astrolog have been distributed with

source code In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the w ...

, and the most recent versions are

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, no ...

under the

GNU General Public License The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general ...

. Several different parties have contributed to the core program or to alternate versions of it. For example, Astrolog started with the early astrological formulas implemented by

Michael Erlewine John Michael Erlewine (; born July 18, 1941) is an American musician, astrologer, photographer, TV host, publisher and Internet entrepreneur who founded the music online database site AllMusic (previously known as All Music Guide) in 1991. Car ...

. Later versions of it made use of the Placalc and then Swiss Ephemeris libraries produced by Astrodienst AG. Other parties contributed PostScript graphics, and integrated ephemeris files for minor planetary objects. Astrolog has been ported to many different platforms, where versions exist for

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, an ...

MS-DOS MS-DOS ( ; acronym for Microsoft Disk Operating System, also known as Microsoft DOS) is an operating system for x86-based personal computers mostly developed by Microsoft. Collectively, MS-DOS, its rebranding as IBM PC DOS, and a few ope ...

, Microsoft Windows,

Macintosh The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and software en ...

OS/2 OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 r ...

, and Amiga, among others. Astrolog has also been distributed as sample packages with versions of SUSE Linux. Some consider Astrolog to rival commercial programs in quality. In November 1995, The Mountain Astrologer reviewed a number of software programs, where Astrolog was the one freeware program included, described as "good enough to be worthy of review with the main commercial programs". In the 1990s, Astrolog was mentioned a number of times in American Astrology's "The New Astrology" article by Ken Irving, because at the time it was the only readily available program that could compute Gauquelin sectors as described by astrologer

Michel Gauquelin The Mars effect is a purported statistical correlation between athletic eminence and the position of the planet Mars relative to the horizon at time and place of birth. This controversial finding was first reported by the French psychologist and ...

. All versions of Astrolog include a

command line A command-line interpreter or command-line processor uses a command-line interface (CLI) to receive commands from a user in the form of lines of text. This provides a means of setting parameters for the environment, invoking executables and pro ...

interface. Most criticism of the program is due to command switches being confusing to memorize or use. Windows and Macintosh versions eventually included standard

GUI The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inste ...

. The command switch interface allows all of Astrolog's features to be accessed from shell scripts or to be invoked by other programs. There are a number of online servers that use Astrolog as a back end to generate charts for the user.

External links

Astrolog website with version 7.50

References

{{Reflist Astrology software Cross-platform free software Free software programmed in C++ Software using the GPL license 1991_software