Users of Canon's camcorders have asked for tools like chdk. There is some work happening on various models.
“This HDV camcorder was released in January 2007, and has become a very popular tool for indie...HV20
“There's an official firmware update available which updates version 22.214.171.124 to 126.96.36.199, and you...HF10/100 Firmware Analysis
“HD camcorder based on the HV20, the HV30 offers some physical body improvements as well as a new...HV30
“The HF10/HF100 is an AVCHD camcorder (saves footage to a SD card in AVCHD format, compared to...HF10/HF100
“Canon has released an update to version 188.8.131.52. Where and how to get the firmware and a serial...HV30 Firmware Analysis