This is Munin.

Munin is distributed under the GNU GPL version 2.  Munin is copyrighted
2002-2012 by its various authors as identified in the source files.

Munin is homed at http://munin-monitoring.org/.  After you have completed
the INSTALL all the documentation can be found there.

There is a somewhat ragged set of contributed HP-UX specific plugins
requiring various licenses.  We hope for further contributions to
make the HP-UX support more complete.

Please note that Makefile.config needs editing almost at the very end
to work, the sections are commented.

You will also need GNU Make which you can find here:

Europe: http://hpux.asknet.de/hppd/hpux/Gnu/make-3.81/
US and other places: http://hpux.cs.utah.edu/hppd/hpux/Gnu/make-3.81/

Many thanks to Ralph Grothe for the contributions towards HP-UX support.

Here's a howto on adding the users in the first place:

bash-3.2# dscl . create /Groups/munin PrimaryGroupId 4949
bash-3.2# dscl . create /Users/munin UniqueId 4949
bash-3.2# dscl . create /Users/munin PrimaryGroupId 4949
bash-3.2# dscl . create /Users/munin UserShell /bin/false
bash-3.2# dscl . create /Users/munin NFSHomeDirectory /nohome
bash-3.2# dscl . create /Users/munin RealName Munin
bash-3.2# dscl . create /Groups/munin GroupMembership munin

bash-3.2# dscl . -read /Users/munin
dsAttrTypeNative:PrimaryGroupId: 4949
dsAttrTypeNative:UniqueId: 4949
AppleMetaNodeLocation: /Local/Default
GeneratedUID: 2A56D7FE-00D0-4B81-BAE7-F842E675031D
NFSHomeDirectory: /nohome
RealName: Munin
RecordName: munin
RecordType: dsRecTypeStandard:Users
UserShell: /bin/false

bash-3.2# dscl . -read /Groups/munin
dsAttrTypeNative:PrimaryGroupId: 4949
AppleMetaNodeLocation: /Local/Default
GeneratedUID: F53ACCA3-2CB9-440F-84A6-E2FADC44CB9E
GroupMembership: munin
RecordName: munin
RecordType: dsRecTypeStandard:Groups