I went looking for a piece of software to map 3d fictitious starmaps and wasn't sure I'd find anything, it's one of those things that only roleplayers are really going to use. I was really excited when I came across this program, not only did it seem to do exactly what I was looking for, but I kept finding extra bonus features in it that pushed it way past my expectations.
Firstly, it can handle maps of unbelievable size and complexity. I've generated ones with nearly 20,000 stars, trade routes between them and full systems around each star with asteroid belts, planets, binary planets or stars, moons, space stations and probably more. It does slow the animation down a bit at this high a setting (at least on my computer) but still seems to work fine. That's way more than I could ever need for a space game.
Secondly, it has free plugins available to make it automatically correspond to GURPS: Space 4th edition, which is the game system I use. (I think I also saw a traveller plugin for it as well).
Thirdly, you can either randomly generate your map (that 20,000 stars map took approximately a minute to create) or deliberate place each system on the map. In fact you can even do both, randomly generating a galaxy as background and then deliberately placing the stars you want.
And finally there's all kinds of options for the GM to use this program for record keeping. You can place ships on the map, put GM Notes on planets and all kinds of things.
The more I play with this software, the more I find that it can do. It takes a little while to get used to the interface, but that's not surprising as there are so many options.
I am very glad that I bought this. Totally worth every cent.