(room 522A, Sunday the 13th, from 13:00 to 15:00) "500 Lines or Less" is the upcoming 4th book in the Architecture of Open Source Applications book series (http://aosabook.org). Contributions are already well underway, with close to 30 submissions of peer-reviewed ~500 line programs that are going to be explored in detail in the chapters of this book. This open space is intended to get early feedback on the work done so far, and to brainstorm where this work could be taken.