like lucy said, use Mac Eve Tools
. it's native and it's great.
i also have gtkEveMon
in case you're interested, which is a gtk version that runs on linux and mac. it's tough to find and i remember i had to compile it myself and hack an old gtk wrapper i found lying around. the version i have implements the character planning part of EveMon. i only use it for that purpose, otherwise my main tool is Mac Eve Tools as it's skill, cert, and ship planning are superior to EveMon's, plus it looks much better as it's native.
if you're interested i can pass you my gtkevemon through dropbox.