The original author of gkrellm, Bill Wilson, also made PiKrellCam. <https://billw2.github.io/pikrellcam/pikrellcam.html>

Which was/is the best Raspberry Pi Audio/Video Recording, OSD Motion Detect Program. It was made to run perfectly on a RPI Zero with its limited CPU and memory.

I was very sad to learn that Bill passed away in Oct 2021. <https://github.com/billw2/pikrellcam/issues/78#issuecomment-...>

I'm glad gkrellm got a new maintainer and continues to exist.