RMS signs books with it. Many of our members sign their emails with it. Now you can wear it. "Happy Hacking" is more than just a motto or slogan, it's a way of life for many in the free software movement. This shirt proudly proclaims the phrase in bright green on the front. The back has a simple line drawing of a gnu. Buy one for yourself, buy one for the hacker in your life, buy one for a friend. This favorite is one of our most popular designs.