Mondtag is a lunar calendar. It calulates the lunar phase and the signs of the zodiac and interprets them. It also calculates sunrise and sunset and includes MondTip, a tool that shows the data for one day.
Open source project that offer summary and download services on this page is a project that carry out their development work on other open source development sites. Their work is linked to this page via a feature called OFI, and their work is not carried out here on OSDN site.