AdHack is a do-it-yourself advertising platform that allows users to create, test, and distribute ads. It functions as a distributed ad agency and ad marketplace. Users can create ads, provide feedback to refine ads, and buyers can choose ads. Ad creators are paid from the funds generated from purchased ads. The document welcomes new alpha users, called Alphanauts, and provides an overview of the platform's features and timeline for further development and user testing throughout the summer and fall.