The oddjobd service receives requests to do things over the D-Bus system bus. Depending on whether or not the requesting user is authorized to have oddjobd do what it asked, the daemon will spawn a helper process to actually do the work. When the helper exits, oddjobd collects its output and exit status and sends them back to the original requester.
It's kind of like CGI, except it's for D-Bus instead of a web server.
The original docs are brief but comprehensive. And there's always a to-do list.
The current release is stable. Go ahead and download it and give it a go. The oddjob package is also available in prepackaged form in Fedora and recent releases of your friendly neighborhood Enterprise Linux.