Hijra Islamic Calendar هجرة is an application for viewing the Islamic calendar (also known as Hijri calendar). It features a GUI with a tray applet. It includes both a high-level OOP library and a low-level library which can be used to implement other software that makes use of this type of calendar. It uses a special algorithm which gives much better precision than other known algorithms. It uses integer operations to avoid round off errors in floating point operations.
Astro::Aladin is a an object-oriented interface into the resources provided by the CDS Aladin project. The Aladin Java application is driven in script mode using an anonymous pipe, while high level access to resources is provided by the module which disguises the mechanics of the data access.
Cerridwen provides geocentric planetary data suitable for a broad spectrum of astronomical and astrological applications, with a focus on our solar system. Among its data you will find, for example, the time of the next sunrise or that of the last full moon, or simply the current tropical position of the sun. It comes with a simple command-line utility and a JSON server, but is also designed to serve as a basis for your own application.