For the program idea I have, it requires that the software be written in one binary that is executeable by all major desktop platforms, meaning it needs an interpreted language or a language within a JVM. Either is fine with me, but the programming language has to balance power & simplicity (e.g. Python)
I know of wxPython but I have read that it's support on Mac OS X is fairly limited
Java sounds good & it looks good but it seems almost too difficult to program in
Any help?
I think wxPython is pretty good, though I am not sure what you mean by "support on Mac OS X is fairly limited" but I have been porting a wxPython app (www.mockupscreens.com) to Mac and it wasn't that difficult with few tweaks e.g. some UI elements may not come up as you expected, as wxPython uses native UI elements, which can be an advanatage or disadvantage based on your requirements.
Other good option is PyQT which will give you consistent look on all platforms.
Cross-Platform Programming Language with a decent gui toolkit?