This is UCD SNMP, a derivative of CMU's SNMP package (tkmib part).

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 Tk/perl mib browser 

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