Magic Lantern: a feature-rich replacement operating system for Canon EOS cameras

Magic Lantern is a replacement OS for your Canon EOS camera that you load via a SD card; in addition to a suite of video-recording tools, Magic Lantern allows fine-grained gain adjustments, selection of input sources, wind filters, audio monitoring, and better tools for everything from white-balance to exposure presets to overlays to help with exposure and other settings. The source is available for inspection and modification, of course. (via Four Short Links)