[Xymon] Advantages of Xymon vs Nagios?

[Andrew Rakowski]

I've been using Big Brother since 1999, and Xymon for the last couple of 
years (on a different project at the lab), but recently, a team member has 
suggested that we switch infrastructure monitoring to Nagios, which he's 
been using on other systems he manages elsewhere in the lab.

He's using something called OMD (the Open Monitoring Distribution - from 
http://omdistro.org/ ), which is supposed to improve on the complexity of 
using Nagios.  Our management would like us to do a comparison to see if 
we should switch from our old Big Brother monitoring (which is still 
running well) to a more up to date Xymon or convert instead to OMD/Nagios.

Looking for information on Xymon and Nagios comparisons, I found this 
comment from Henrik in the Xymon mailing list archive:

     http://lists.xymon.com/archive/2006-June/007530.html

that mentions the ease of setup and use of Xymon as compared to Nagios, 
but that comment is nine years old.

Daniel's recent comments on this list about wanting to move from Nagios to 
Xymon:

On Fri, 6 Feb 2015, LOZOVSKY, DANIEL L wrote (in part):
> Subject: Re: [Xymon] Installing xymon/apache as a non-root user
>
[...snip...]
> community.  I have been pushing AT&T to utilize xymon instead of nagios. 
> I have been using BB open source version for almost 10 years and it 
> really saved us at Supply Chain.  Of course, I had to make a lot of 
> modifications to it.  Xymon is the next logical step to help make things 
> much better.
[...snip...]

has me wondering what I can point to as good reasons to use Xymon vs 
Nagios, as certainly, people do want to switch.

So, what are reasons that folks like Xymon better than Nagios (besides all 
the helpful info from the great group of folks I've been reading during my 
years of lurking on the list...)?

Best regards,

-Andrew