controlling multiple leds with processing

Hi, I’m trying to figure out how to control multiple LEDs from Processing, using different data sets as control parameters for each LED. I’d like to do something as simple as having each led continually flash at a different rate based on different values passed on from Processing. I can’t even get the arduino to output different flashing rates simultaneously using the digital pins.
Is it possible to use flash multiple LEDs at diffferent rates simultaneously?
thanks.