What is CHDK?

• Canon Hack Development Kit
• Temporary – No permanent changes are made to the camera.
• Experimental - No warranty. Read about the risks in the FAQ
• Free – free to use and modify, released under the GPL.

Features

• Professional control - RAW files, bracketing, full manual control over exposure, zebra mode, live histogram, grids, etc.
• Motion detection - Trigger exposure in response to motion, fast enough to catch lightning.
• USB remote - Simple DIY remote allows you to control your camera remotely.
• Scripting - Control CHDK and camera features using uBASIC and Lua scripts. Enables time lapse, motion detection, advanced bracketing, and more.
• more : CHDK Features and CHDK in Brief