I don't see what good including a DLL with mIRC will do. In order to benefit from it users must have some kind of script using it, meaning they still have to download something - why not have the DLL in the download aswell? In fact they must have the DLL in the download aswell, otherwise there can be no guarantee that the version currently available to one user's mIRC will be acceptable for any given script since even if they require a specific version of mIRC there's no guarantee that the user hasn't chosen to "upgrade/downgrade as they see fit".