StarCalc is the fastest professional astronomy planetarium & star mapping program. 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 semispherical whole sky or any of the user defined sub-areas. These images can then be rotated, zoomed at different scales, printed and screen-captured. Also, StarCalc has many other functions of calculation and showing of sky objects.