as someone who regulary writes software for linux and windows i dont get this at all. the only way it would be difficult to port software to linux is if you're using something like directX or some libraries that you didn't write yourself in windows. if you're directly manipulating theVOB files and used a decent programming language like c or c++ then it wouldn't be impossible to do. if you used something stupid like a windows visual based tool...then that's bad.
visual tools should only be used for theGUI