StarCalc is the fastest professional astronomy Planetarium & Star mapping program for Windows 9x/ME/NT/2000/XP (StarCalc version for PocketPC computers you can find here). It illustrates star positions of any instance of the day observed from any geographic Locations on the Earth. The star positions can be viewed and presented as images of hemispherical whole sky or any of the user defined sub-areas. These images can be zoomed at different scales, rotated, screen-captured and printed. Also, StarCalc has many other functions of calculation and showing of sky objects. Best of all StarCalc is freeware.
Extensibility: This program is based on common 'Plugin StarCalc interface to catalogs and object groups', which allows program to add new modules as plugins. These modules enable the program to use astronomy catalogs support and many others add-ons down the road or directly from other vendors.
Fast performance:: extra efficient algorithms allow the program to calculate a sky image in a fraction of a second even just on very old computers.
User friendliness: StarCalc has a simple interface, most operations are implemented by mouse. The program employees the WYSIWYG technology (What You See Is What You Get), which helps you to print a detailed image of any enlarged area of sky in its finest astronomical Details.