Galactic is a Traveller star map generator and display program. It was originally written for DOS using QuickBasic and displays on a VGA screen in 16 colors. Jim Vassilakos has released Galactic into the public domain.
Despite its obvious technological backwardness and age, it remains a well-used and almost essential piece of Traveller software because of its utility. It is simple to use, runs on many computers (in a Windows DOS box, or under DOSEMU for linux). All of the program data is kept in human readable text files. The formats used for the UWP data remain a standard in the Traveller star mapping community.
The latest version (gal23c.zip) contains several galaxies, including maps of the classic era, Interstellar Wars, TNE, Milieu 0, and two variant Traveller universes. The format of the data is in the Galactic File Format.
From the online writeup:
Allows user to randomly generate sectors, displays the maps in VGA, translates the UWP code to English, and keeps campaign notes in text files which can be accessed directly from the map. The maps all mesh seemlessly. Lots of official & non-official Traveller sectors are included. There's even world mapping and star system mapping software. Contains enough online help that it can be used by someone who has never before played Traveller and is just getting into it.