I've heard good things about syslog-ng, and it seems to be a good way to make secure, centralized logging possible for Linux machines. (Ex: http://www.serverwatch.com/tutorials...le.php/3600641)

I have found the organization that makes syslog-ng, but they appear to charge money for this package on Linux. However, some articles on the Internet claim that syslog-ng is standard on all Linux operating systems. Is this true, or will I need to pay the vendor money?

If anyone has any recommendations for software to use for centralized logging, I would also be interested to hear of those packages. Thanks in advance.

There is definitely a free version. It comes standard with fedora and ubuntu(i think)
use yum or apt-get to search for it.