I have a Windows 7 Desktop PC.
The Sky was recommended by someone I trust. Your website info convinced me that this is very likely the astronomy software I will purchase. Here's the obstacle: I want to purchase your software NOW for my desktop PC to learn its operation, and I will need to reinstall it later when I get a laptop for the field. I understand this is possible to do.
However, I haven't decided whether I want to bother relearning MS-Windows because I'll be forced to upgrade to Windows 10, or use this opportunity to switch to a MAC. It isn't an arbitrary decision. There are other software products I would have to purchase, too, and need time to decide which choice I should make. (Besides, I'm hoping Mrs. Claus will fill my stocking with the laptop, so I'll need to wait, anyway.)
Q. - If I buy now for Windows, but later decide on the MAC, will I be allowed to switch over, or will I have to buy another license for the Macintosh? Assuming I only need one license, could I retain a Windows version on my PC Desktop and use a Mac version on my laptop?
~lebie