Is it possible to modify the speed at which alert messages appear at the top of the screen? I referring to the text that appears in the transparent area at the center-top of the screen. Messages like "Montezuma has adopted Democracy" appear there.

I find the slow speed at which these appear to be annoying. Sometimes, I'm well into playing my next turn when messages from the previous turn are still appearing. Its rather aggravating to be making decisions, which are irreversible in this game, only then to have a message appear a long time after the last turn resolution is done that tells me something I wish I had known.

Or, I've lately been playing the Rise of Mankind mod, which has a ton of messages appearing about archery units and bombard units firing. The messages themselves are useful as they help me to understand this new form of combat. But, I recently just fought a big battle where an AI attacked me during its turn. These archery messages from that battle are still dribbling in a good ten minutes into my turn.

So, is there anything like an "Instant Messenger" mod that would make these messages appear faster? Or, is this something that I can go edit to my tastes myself?

You can always look at the event manager, which will show a list of all events that have occurred. I forget the key button combo for it, but in RoM it is the button right below the civilopedia button. I open that up and look at it.

This one the mod maker himself is responsible for. When you set a message to be displayed in that area, you have to choose how long to have it display for, and decide if it should bump the list immediately, skip if the list is currently full, or wait in line till it can take a turn at delaying other things in the line after it.

Combat type information really ought to be set to display briefly, and only if the list has space/time available (ie - not hop in line and wait a turn if you are already behind), since to really process it most people would want to open the event manager anyway, or even the full combat tab, and they are just a "heads up" otherwise.

If the mod uses the "standard" method, it is basing the times on global settings.

Try reducing the value of EVENT_MESSAGE_TIME from 10 to 5, EVENT_MESSAGE_TIME_LONG from 20 to 10, and EVENT_MESSAGE_STAGGER_TIME from 3 to 2 (these are in GlobalDefines.xml).

This may help.