Hacker News on 20 September 2013

• A beginner's cheat sheet for web development
• Show HN: UI Concept – Focus Transition
• Mozilla Labs: TogetherJS
• Cmd.fm
• My Daughter’s Homework Is Killing Me
• Einstein and the Great Fed Robbery
• FreeBSD 10′s New Technologies and Features
• Less is exponentially more (2012)
• How airline reservations are used to target illegal searches
• Beginner's Guide to Wi-fi Interception