I'm under the impressions that Python runs in the Triforce smoothly. A program that runs in Windows will run in Linux. Is this sentiment correct?
Having said that, if I create my application in QT For Windows, will it run flawlessly in Linux/Mac as well?
Thanks.
It might run well, but it will take some testing, and of course Qt only handles the GUI portability, not the myriad of other things that might cause portability problems.
Qt apps generally don't fit in very well on MacOS because they don't have Applescript support by default and don't necessarily have the right keybindings.  But if you do the work to fix those issues, they work, but not nicely.  On the Mac, it's far better to build a native UI.  If this is an in-house app, Qt is probably OK, but if it's for sale, you won't make many sales and will create yourself some support hassles.
If I use QT For Windows, will my application run great on Linux/Mac/Windows?