Yup, been using it since all the new Macs came out! It's great, works with any sort of screen name you want - AIM, Gmail (through Jabber as well - a different feature worth reading up on), your Mac email address (assuming you have made one), etc. The bubbles are fun, and I've always liked being able to re-format incoming messages - good for the days when my fellow teenagers thought that a size 16 font in hot pink was *cool* !