preactive, proadaptive, preemptive, pre-action, foreprepared, preactivity, forethoughtful, proleptic, preadaptive, early, more...

reactive, passive, inactive, unresponsive

taking initiative,   action oriented,   takes initiative,   action taker,   pro active,   not procrastinating,   having initiative,   showing intiative,   willing to initiate,   shows initiative