This is Net-SNMP (previously known as "ucd-snmp").

Various tools relating to the Simple Network Management Protocol including:

    An extensible agent
    An SNMP library
    tools to request or set information from SNMP agents
    tools to generate and handle SNMP traps
    a version of the Unix 'netstat' command using SNMP
    a graphical Perl/Tk/SNMP based mib browser

WWW: http://net-snmp.sourceforge.net/