Four short links: 22 September 2011

Implicit and Explicit Feedback — for preferences and recommendations, implicit signals (what people clicked on and actually listened to) turn out to be strongly correlated with what they would say if you asked. (via Greg Linden)
Pivoting to Monetize Mobile Hyperlocal Social Gamification by Going Viral — Schuyler Erle’s stellar talk at the open source geospatial tools conference. Video, may cause your sides to ache.
repl.it — browser-based environment for exploring different programming languages from FORTH to Python and Javascript by way of Brainfuck and LOLCODE.
Twitter Storm (GitHub) — distributed realtime computation system, intended for realtime what Hadoop is to batch processing. Interesting because you improve most reporting and control systems when you move them closer to real-time. Eclipse-licensed open source.

Feedback, Open Source Marketing, Programming in the Browser, and Twitter's Open Source Realtime Engine