ClamAV , OpenAV, Spamassasin

For the Network Monitoring tool

Nagios, Munin , Wireshark, Tcpdump, Ettercap, Nmap, Big Brother
SNMP tools like
MRTG
For the single sign on OPENLdap ( and I bet you there can not be any better than that)
We generate free RSA authentication for Openssh
Apache , Mysql , PostgreSQL , Sendmail , Postfixmail ,
And there are many more tools that our company is using  and saving ton's of $$ . I wish you get your fat bonus next year or Never if you don't.

I'm not here to discuss about the free or commercial products.

Xantu "opensource4us" and "sysadmins" - don't quite tally, do they?" is not my statement
Let's get this straight. You help me out figuring how to operate any commercial products out there and I'll help you with the Opensource one.

It's all about sharing the information . If you don't like it , its ok.
I know everyone is here to make some fat $$$$$ ( Like all the commercial Products)
and there are some who happy for those who cannot afford  to pay.

Dude , understand this. I know some really good admins working here and are really wonderful people.

No hard feelings Saajha , you took this thing other way...