Emonitor is a project mainly written in C, it's free.
emonitor is a monitor plugin for fbpanel
NAME emonitor is a monitor plugin for fbpanel
DESCRIPTION Emonitor is plugin for fbpanel, which shows output of external programs on the panel. Using this simple plugin and external scripts (in bash, python, ruby, perl...). You can print system information on the panel.
AUTHORS Viacheslav Chumushuk [email protected] http://code.google.com/p/emonitor/