Hello titobal,
IceDesign runs only under Windows but the generated code is written in native PB code without OS specific code, API... It should be 100% compatible with MacOS or Linux.
But this, as long as some Windows styles are not selected to stay Cross-Platform.
They are well marked in the properties constants list for this. They are at the bottom and they start with a # (ex for buttons: #BS_Bottom, #BS_Top).
However, I do not have a Mac to test and see the result.
There are probably small adjustments to be made for the Gadgets size and position and to add a Menu (#PB_Menu_Quit) to close the Window, see mk-soft's example.