GitHub has launched two t-shirt designs available for purchase through rubyrags.com, featuring playful slogans related to software development. The classic "Fork You" shirt is known for drawing attention, while the new "All Your Rebase" shirt offers a humorous nod to those familiar with version control systems, particularly in jest towards SVN users. Both designs are printed on high-quality American Apparel shirts in Asphalt color, and customers are encouraged to personalize their shirts by writing their GitHub username on the back. GitHub invites buyers to submit photos of themselves wearing the shirts for a chance to be featured on their blog, offering a fun way to become "GitHub Famous."