We need to build Mac packages on the fly and it would be convenient if there is a way to create the same on Windows or Linux platform instead of using PackageMaker on Mac. Any ideas?
Nope, you can't. You could do a scripted ssh login and fire it off using osascript so you can automate the whole build from somewhere else, but you can only build for a Mac on a Mac.
You could do all the builds on a Mac, though. It's much easier that way around.