I created a few scripts for use with the Planets.nu site/game. This web page describes those scripts.
I also run a few services to assist Plugin Developers and Game Hosts.
A service of this nature is useful because the in-game messages about players entering and exiting the game are not transmitted to the Host, or to other players. In addition, this service performs a small amount of research on the entering players, to help the Host. This service will be most useful in games where the Host isn't playing.
When a player leaves a game, and the position is marked by the system as "open", the Host receives a PM. This allows them to advertise the availability of an open position on the Activity Feed, and, if appropriate, pause the game. When a player slot is set to "dead", no message will be sent, as this does not require any action from the Host.
When a new player enters the game, a PM is sent to the Host. That PM includes the player's ID, and race. It also contains information on how many times the player has resigned/dropped or died in the last 10 and 20 games (up to the limit of the games the player has been in - see sample message at the end of this post). Finally, if the player has been a recipient of the Tim Continuum, that information will be included in the PM.
When a game is added to the list of monitored games, the above information will be sent to the Host on all active players.
At this time, the only known action that a Host can take to remove a player from the game is to pause the game and request that the unwanted player leave. If this doesn't work, the Admins might respond to a request from the Host to remove a player from a Custom game (I don't know their policy on this). For Hosts who want a bit more control over their game, please vote for "https://planets.uservoice.com/forums/136520-general/suggestions/19286422-allow-a-game-host-to-eject-players-from-games-they", and/or send a message to Big Beefer requesting this change, or something similar.
The game summary sent to the Host includes all games (up to 20) that a player has been in (Resigned, Dropped, Dead or Completed), including games as a replacement, and MvM games.