Net-SNMP

cd /usr/local/src/net-snmp-5.4.2.1

./configure --prefix=/www --with-default-snmp-version="3" --with-sys-contact="boiarino@jlab.org" --with-sys-location="bldg97room102A" --with-logfile="/var/log/snmpd.log" --with-persistent-directory="/var/net-snmp"

You are about to be prompted with a series of questions.  Answer
them carefully, as they determine how the SNMP agent and related
applications are to function.

After the configure script finishes, you can browse the newly
created net-snmp-config.h file for further - less important - parameters to
modify.  Be careful if you re-run configure though, since net-snmp-config.h
will be overwritten.