Outside of Hollywood, how could some one make software that can be relatively easy to port from platform to platform?
Use an OS-agnostic APU like SDL, QT, GTK, WxWidgets, etc. in C, C++, etc. If we had Java JVM, that could be another option.
My favorite is WxWidgets, as one of the mian goals wiht it is to make an app appear and behave as an OS-native one. Other of these APIs may look foreign on your OS of choice, such as a QT app always looking like a QT app, regardless of what OS it is running on. WxWidgets apps intend to look like MS Windows app on MS Windows, or look like an OSX app on OSX, etc... I'm really hoping we get a WxWidets port to AmigaOS and -alikes. If only I had free time...
Is there any reason why software can not be made for Amiga os anymore?
No. I just bought Stormc4 a few days ago...