The Virtual Observatory Quantity Data Model (VOQDM) package is a "thing"-based data model for use with scientific and mathematical data in the International Virtual Observatory (IVO). It is built upon the QML (Quantity Model Language) package and, in general terms, enables fast, convenient serialization/deserialization/manipulation of Quantity-based objects and documents. An important specific application for this package is to enable the I/O of VO-catalog-based data.
Simulum deals with different simulations of star movements and their visualizations. At first it looks at the projection and accumulation of star brightness. In actually doing this it distributes stars among a three dimensional figure. To get a nice effect it combines the photographic image production with a moving view point. So the outcome is the visual impression of flying through a star field. Secondly it studies different algorithms of particle movements and clustering. The primary approach uses a combination of Newton's gravitational law, energy, and impulse conservation. At all these stages an highly dynamic view of the processes is able to be produced.
INDI is an instrument-neutral distributed interface control protocol that aims to provide backend driver support and automation for a wide range of astronomical devices (telescopes, focusers, CCDs, etc.). Current supported devices include many telescopes, CCDs, filter wheels, focusers, and video cams. INDI is used in popular astronomy suites like Xephem, KStars, DCD, and Cartes Du Ciel.
libnova is a general purpose, double precision, celestial mechanics and astronomical calculation library. It can calculate aberration, nutation, apparent position, dynamical time, Julian day, precession, proper motion, sidereal time, solar coordinates (using VSOP87), coordinate transformations, planetary positions (Mercury - Neptune using VSOP87), planetary magnitude, illuminated disk and phase angle, lunar position (using ELP82), phase angle, elliptic motion of bodies (Asteroid + Comet positional and orbit data), asteroid + comet magnitudes, parabolic motion of bodies (comet positional data), orbit velocities and lengths, atmospheric refraction, rise/set/transit times, and semidiameters of the Sun, Moon, planets, and asteroids.
libAstronomy provides a set of astronomical routines to ease the calculation of ephemerides. It includes mathematical functions to compensate various astronomical phenomena like precession, nutation, etc. The getconstellation routine finds the constellation for a given coordinate. It also calculates the positions of the sun and moon in two different precise ways.