Well, other Greasemonkey scripts could use it, too.
Cicero, that could work. I'll have to write functions to get different sets of countries, with ones to get such sets as:
All of a player's
All with a certain amount of armies
All with more than a certain amount of armies
All with less than a certain amount of armies
Bordering would work a bit differently, since instead of just comparing sets, it would take a set and give back a different set.
But with a proper combination of those sets, you could have it report things like:
All of your enemies pieces which have less than 3 armies and don't border another country owned by your enemies, that happen to border countries of yours with more than 4 armies
It'd just tell you all the countries it'd be easy for you to take, in theory.
I can imagine that being useful, especially on crazy maps like Age of Merchants where with all the ports, its hard to keep track of what you want to know.
Of course, you wouldn't have to write that every time.
Does anyone think I should ask stocksr if I could use his board xml reading and hilighting code?