Tetrabyblos is an extremely easy Word Press plugin to install and manage, which allows for any cyber user to get his personal astrological chart from your website - along with a transits calendar - and, if you wish so, to obtain a first preliminary Interpretation report completely written and controlled by you. This is an innovative and, we like to think, precious and necessary plugin which does not exists as an independent script, on the world market of web services - thus the Word Press format for implementation in order to facilitate its use. The plugin is responsive - so it fits itself from a laptop to a simple android.

Version 1.1, computes the following parameters:

Ecliptic tropical/sidereal longitude of the major celestial bodies/points (Sun to Pluto, Lilith, ascendant. Mid-heaven, moon nodes and the eight major Arabic Parts), about 60 important astrological stars and the cusps of the houses - both for radix (birth chart) and current transit.
Enumerates the Dignities (including Terms and Faces), Elements and Qualities (with percentages) of the planets and the most important aspects between them.
Draws the graphical chart - with birth and transit - and the table of aspects.
Gives the primary astrological Vedic - Jyotisha - information for that chart: Nakshatram, Yoga, Karana, Thiti, Pada, Rasi, madhya/sandhi houses, and Dasa periods (birth and current). By default, uses the Lahiri Ayanamsa when the tropical chart is requested for mutual comparison of both systems. Coordinates both of the Rasi and the Nakshatra are given, with Pada and house position.
Has 13 different House systems at your disposal (like Placidus, Porphyrius, Equal, Regiomontanus, Campanus, Morinus, Koch, Topocentric, etc.)
Has 13 different reference Ayanamsas (like Lahiri, Fagan/Bradley, DeLuce, B. V. Raman, etc.).
Has a built-in atlas with almost 145500 cities in the world, with historical time zone calculations or manual if you wish so. You can either choose from the atlas, or introduce yourself the geographic coordinates and time zone offset of the place of birth.
Accurate astronomical calculations for the period of about 6000 years (from about 3000 B.C. to 3000 A.C.).

Added features in version 1.2:

Zoom natal chart.
Scale form to fit better to the template design.
Enable/disable advanced features to the users.
Enable/disable soft astrological aspects.
Show/hide bodies/points like Chiron, Lilith, Rahu and Ketu, Syzygy or Pars Fortuna or the solar sign glyph.
Show/hide Vedic report.
Max Heindel interpretations by default.

Added features in version 1.3:

Important feature: Possibility for making a simple zip backup of your own interpretations texts - and download it - and restore it automatically from the zip. This feature is useful and indispensable, since a mere upgrade or misconfiguration could make you lose all your reports and/or drafts. You can, also, always restore the default Max Heindel texts (zipped texts are inside the Documentation folder).
Select essential dignities table system between Ptolemy and Dorotheus.
Calculate the essential dignities scores (according to the table chosen).
Capability of uploading custom images for the signs and planets, to be used in the text reports, with the size you define, if wanted. You can chose not to show any image, show only the ascendant sign customized image, the ascendant and the most dignified body, or all the bodies.

Added features in version 2.1.2.0:

Complete control on showing/hide all the report section.
More visible background for the zoom.
Implementation of solutions for users who don't have the most basic permissions (like some php ini default values).
Ability to use some parameters in the shortcode plugin.

Added features in version 2.2.2.0

Implementation of a complete Transits calendar with customizable written reports for any date.
One bug fix regarding some astrological points math and formula.
Improvements and fixes regarding the essential Dignities tables. Mutual receptions were implemented. Now, you have the option to customize your own custom dignities table (besides the classical ones of Ptolemy and Dorotheus) and have the choice between using 2 different score systems (basic and with m.r.).
Show (optional) a small but accurate Astronomical events calendar, of the seasons and eclipses (lunar and solar) for the year of birth along with all the four moon phases for that month.
Possibility of choosing Pars Fortuna formula.
Improvement of the admin interface.
The user data is now stored in cookies - if he allows it - and loaded when he enters the website (only if cookies are enabled in the web browser and the visit is no longer than 7 days apart).

Added features in version 2.2.4.0

Implementation of about 90 additional Arabic Parts.
Possibility of hiding the outer planets (Uranus, Neptune and Pluto) in the results.
Small fix in the Libra sign glyph and in the aspects colors.
Implementation of visual options for the natal chart: 1) Choose between showing only the Radix chart or also the Transits one. 2) Choose a black and white chart if you wish (instead of a colored one). 3) Control de scale size of the glyphs.

Added features in version 2.3.0.0

Implementation of multi-language support (a feature many times requested). Now, most of the major and more important texts and strings on the plugin show to the user, can be translated manually by you, without having to resort to the paid Google translator API. The admin panel was not yet translated.
Insertion of the new glyph of Unfortunate or Sickness – along with the Pars Fortuna.
Now, the transits page, when called not from the major plugin form, automatically asks for the birth details. So, you can implement a birth chart page, and a transit one only.
Minor bugs fix.

Added features in version 2.3.1.0 - Latest

Minor bugs solved. Implementation (in beta test phase) of the print capability (optional), so the user can print his/her chart and information.

Besides these characteristics, you have the possibility of write and define your own natal and transit interpretations texts and manage them in the Word Press administration panel giving the visitant the possibility of getting a personal report "on the fly"