Debian
Debian GNU/Linux is a free operating system with a focus on stability. It's based on a sophisticated package management system that lets you choose from three releases of varying stability. The software packages included in the stable release have been tested thoroughly and are ideal for a server environment, whereas testing and unstable releases have more recent versions of software which usually contain some bugs. Ironically, Debian's unstable release is often more stable than many other distributions' final releases.
Debian/ZM installation notes
thorough Debian/ZM installation guide using a zoneminder debian package which requires unstable ffmpeg/libavcodec2/liblame0
yet another Debian/ZM installation guide - package selection and compiling ZM from source (without ffmpeg) in a few quick steps
/etc/init.d/zm script - slightly modified from the original to correctly echo output on debian