Stellarium is a free open source planetarium for your computer. It shows a realistic sky in 3D, just like what you see with the naked eye, binoculars or a telescope.
It is being used in planetarium projectors. Just set your coordinates and go.
Linux
Stellarium
Categories: Analysis & Modeling
Omeka
Categories: Design & Visualization
Omeka is a free, flexible, and open source web-publishing platform for the display of library, museum, archives, and scholarly collections and exhibitions. Its “five-minute setup” makes launching an online exhibition as easy as launching a blog.
Omeka is a Swahili word meaning to display or lay out wares; to speak out; to spread out; to unpack.
Omeka falls at a crossroads of Web Content Management, Collections Management, and Archival Digital Collections Systems: 
Omeka is designed with non-IT specialists in mind, allowing users to focus on content and interpretation rather than programming. It brings Web 2.0 technologies and approaches to academic and cultural websites to foster user interaction and participation. It makes top-shelf design easy with a simple and flexible templating system. Its robust open-source developer and user communities underwrite Omeka’s stability and sustainability.
CentOS Linux
Categories: Operating Systems
CentOS (abbreviated from Community Enterprise Operating System) is a linux operating system that serves as the free, open source, functionally compatible mirror to Red Hat Enterprise Linux, its upstream source of code. CentOS is often used by amateur developers or server administrators for testing purposes, or even in a live production environment.