If it can be, that is.
I have seen time and time again on this web board ideas and requests for EV: Nova plug-ins that, while good, are hopelessly impossible due to limitations of the game engine and the means by which plug-ins are created and used. There have also been ideas that do work, but are quite clumsy in their implementation and use large amounts of the engine's resources, most notably Nova bits. However, I have found a way to fix these and other problems that may otherwise hinder the development of a plug-in.
In the unlikely event that someone was granted the permission by Matt Burch to create an EV4, this is how the plug-in and data files should work.
Today's EV, like those of yesteryear, use static boxes that you fill in with numerical values with a tool like Res Edit, Mission Computer, or EVNEW. The engine reads the numbers and uses them to determine things like max accel for a ship, the damage a missile can do, what mission to offer next, exc. The problem is that there is not a lot of flexibility in working with these boxes and numbers. Sure, you could do something fancy to create a means of storing and retrieving ships for later use, but this usually uses up an exorbitantly large number of resources. The solution is to do away with the confining boxes and instead use a custom scripting language.
This idea is not new. In fact, this is exactly how the popular, free, open-source game Battle for Wesnoth works. To create a plug-in, you come up with an idea, open up the text editor of your choice, write the plug-in in the scripting language, save it as a .txt file, replace the .txt extension with a unique extension that the engine keeps an eye out for (ex: .ev4p), and your done.
For example, lets say you wanted to create a weapon that when fired would drain a ship's fuel and recharge the shields (something I understand to be impossible in EV: N).
{
upon weapfireon
fuelmod: -5
shieldmod: 3
}
The possibilities are endless with such a system. Granted, the simplicity and ease of use associated with the box and number system has been thrown out the window. The benefits, however, are well worth it. You want a weapon that shoots out the side of your ship? That can be done. You want to make the AI tougher? As long as the programmer throws in that feature, you can do that too. Want another location on the planets, like a store separate from the market? That could also be done. As an added bonus, the Mac plugs would work on Windows machines, and vice versa, with no need to convert, because both machines understand and can read and write text files.
Such a system, however, would require a lot of time and energy to develop and maintain. It would take a very dedicated programmer or programmers to create not only a brand new game engine, but also a new scripting language. It could take years. Of course, this is assuming that Matt Burch allows an EV4 to be made. It does not look like that is the case. So we are left here to speculate what could be.