The Harnic Astrology program takes a fully functional and richly detailed Earth-based Astrology Program ("SymSolon") (GNU) and changes the parameters to produce output appropriate for the Harnic Isles and the planet (solar system) of Kethira.
This article details Hârnic currencies, the operation of Royal Mints, Counterfeiting, Usury, the Lore skill of Numismatics, and 30 rare coins that might turn up in a character's purse.