Will it require everyone to download and run a mod for it to work or can it just run server side and everyone join as usual?
Sorry; I don't think there is any possibility for most of the features to be compatible with unmodified Native.
To be specific, the only features that work when just applied to your client are the new voting keys and the adjustments to the poll presentation (I've been playing on the servers with them for a week or two already). Features that can be applied to the server and some clients - keeping compatibility with unmodified clients - are the poll admin override (modified to remove the different poll result message on the clients), and sending the poll name and reason for all polls except the "map and factions" one, which is probably the most common annoying poll; it uses up all the available network message values, leaving none to spare. All other features effectively require a new mod, as they add new network message types or change the meaning of some values in existing messages.
. It started simply as an attempt to make a server side patch to show the requester name and kick/ban reason - which unfortunately couldn't be completed, as previously explained. So then I decided to try implementing a few other ideas I'd had and suggestions I'd read around the forums, which in some cases turned out to be easier than I expected. One of the reasons I decided to release this now was that I'd run out of good ideas to try; if people give me more good ideas or feedback about what they dislike and want changed, I'll probably try to implement them. I'll also keep it updated as new versions of the module system come out.