Thanks. I'm still trying to configure processing to communicate with my arduino Uno, and it's been taking days. I did revert to processing 1.5.1 (thanks for the suggestion) and I've found the arduino libraries and added them to processing. Now I'm trying to solve the "infamous" RXTX mismatch problem. There are many, many posts on this on processing and other places, but it's overwhelming and I have not found a simple step by step way to get this working. I do not have experience with Java, jar, binary, etc - can you suggest a very, very simple tutorial for a first Arduino-Mac communication with processing? I'm trying to keep it simple, just trying to blink an LED on my arduino, but I can't get past the configuration issues. Thanks.