Openfire - Install on Linux or Windows

We've been running it on a Win 2k3 box that was also one of our DCs. We are about ready to decommission that server completely.

I need to install openfire on a new virtual server. I have pretty limited experience with Linux, but would like to learn more. We have a volume license for 2k8 r2 and I am more familiar with Windows. Is there an advantage to running it on Linux. The chat has only been available to a few people in our organization, but I plan on rolling it out to everyone. It will slowly become mission critical.

Thanks in advance for any advice!