1. Mount & Blade: Warband
2. http://www.mountandbladewarband.com
3. The problem with this area is that the servers listed within Warband are identified by name and properties only. There are no IP's listed like with Valve games etc. There are currently 350 servers on line with a total of well over 2000 players.

The modification community itself is abuzz and proof of this can be found here; http://forums.taleworlds.com/index.php/board,165.0.html
In addition the game community itself is as strong as ever, as demonstrated by the amount of new posts per day found with the link below;
http://forums.taleworlds.com/index.php#c8

I hope this is a good substitute for what you require

1. Game: Mount & Blade Warband + Napoleonic Wars DLC (if that matters)

2. Web page: https://www.taleworlds.com/en/Games/Warband

3. There is no way to get the IP of the servers that I know of outside of being the owner of a server, but if you open up the game in either the Native or Napoleonic Wars module, you will see hundreds of servers across the two that are always populated.

There is a very centralized community for Native Warband on the Taleworlds forum and Napoleonic Wars on the Flying Squirrel Entertainment forums (fsegames.eu).