Astrolog is an open-source astrological software program that has been available online free of charge since 1991. It has been (as of 2024) authored by Walter Pullen since its creation, and was originally distributed via postings to the

Usenet Usenet (), a portmanteau of User's Network, is a worldwide distributed discussion system available on computers. It was developed from the general-purpose UUCP, Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Elli ...

newsgroup . Astrolog can create

horoscope 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 ...

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

asteroid An asteroid is a minor planet—an object larger than a meteoroid that is neither a planet nor an identified comet—that orbits within the Solar System#Inner Solar System, inner Solar System or is co-orbital with Jupiter (Trojan asteroids). As ...

s 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 an orbital semi-major axis of 30.1 astronomical units (AU). ...

s such as Eris, Haumea and Makemake, uranian objects such as Vulkanus and Russian Proserpina, and 27 different planetary moons. It can show nearly 50 fixed stars, display

exoplanet An exoplanet or extrasolar planet is a planet outside the Solar System. The first confirmed detection of an exoplanet was in 1992 around a pulsar, and the first detection around a main-sequence star was in 1995. A different planet, first det ...

transits, and animate the chart in real time synchronized with the OS clock. Astrolog can do forms of locational astrology such as

astrocartography Locational astrology (sometimes referred to as astrocartography or astrogeography) is any of various types of astrology that factor in specific locations of the Earth. The different types also carry a range of astrological techniques. Astrogeogra ...

. Recent versions use the

tz database The tz database is a collaborative compilation of information about the world's time zones and rules for observing daylight saving time, primarily intended for use with computer programs and operating systems. Paul Eggert has been its editor an ...

for

time zone A time zone is an area which observes a uniform standard time for legal, Commerce, commercial and social purposes. Time zones tend to follow the boundaries between Country, countries and their Administrative division, subdivisions instead of ...

and

daylight saving time Daylight saving time (DST), also referred to as daylight savings time, daylight time (Daylight saving time in the United States, United States and Daylight saving time in Canada, Canada), or summer time (British Summer Time, United Kingdom, ...

detection. All versions of Astrolog have been distributed with

source code In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer. Since a computer, at base, only ...

, and the most recent versions are

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

under the

GNU General Public License The GNU General Public Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...

. 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, publisher, and Internet entrepreneur who founded the music online database site AllMusic (previously known as All Music Guide) in 1991. Career Erle ...

. Later versions of it made use of the Placalc and then Swiss Ephemeris libraries produced by Astrodienst AG. Other parties contributed

PostScript PostScript (PS) is a page description language and dynamically typed, stack-based programming language. It is most commonly used in the electronic publishing and desktop publishing realm, but as a Turing complete programming language, it c ...

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, multi-user 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, a ...

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 op ...

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

Macintosh Mac is a brand of personal computers designed and marketed by Apple Inc., Apple since 1984. The name is short for Macintosh (its official name until 1999), a reference to the McIntosh (apple), McIntosh apple. The current product lineup inclu ...

OS/2 OS/2 is a Proprietary software, proprietary computer operating system for x86 and PowerPC based personal computers. It was created and initially developed jointly by IBM and Microsoft, under the leadership of IBM software designer Ed Iacobucci, ...

, and

Amiga Amiga is a family of personal computers produced by Commodore International, Commodore from 1985 until the company's bankruptcy in 1994, with production by others afterward. The original model is one of a number of mid-1980s computers with 16-b ...

, among others. Astrolog has also been distributed as sample packages with versions of

SUSE Linux openSUSE () is a free and open-source Linux distribution developed by the openSUSE project. It is offered in two main variations: ''Tumbleweed'', an upstream rolling release distribution, and ''Leap'', a stable release distribution which is so ...

. 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 interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

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 Gui or GUI may refer to: People Surname * Gui (surname), an ancient Chinese surname, ''xing'' * Bernard Gui (1261 or 1262–1331), inquisitor of the Dominican Order * Luigi Gui (1914–2010), Italian politician * Gui Minhai (born 1964), Ch ...

. 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.

References

{{Reflist

External links

Astrolog website with version 7.70
Astrology software Cross-platform free software Free software programmed in C++ Software using the GNU General Public License 1991_software