The YAZ proxy is a single program. After startup it spawns a child process (except on Windows or if option -X is given). The child process is the core of the proxy and it handles all communication with clients and servers. The parent process will restart the child process if it dies unexpectedly and report the reason. For options for YAZ proxy, see the Section called Proxy Usage (man page).
As an option, the proxy may change user identity to a less privileged user.