That will definitely remove it.  Check your logs on the server for any trace errors related to Openfire after you reboot.  There may be failed attempts to start the Openfire server if it was configured to start at boot.  The error logs will tell you what to remove. 

iChat server is fairly good server.  I came from an environment where we used a lot of Mac desktops and servers.  Had lots of fun integrating existing OS X servers into a ne AD server environment.

There are also some very good freeware apps out there that will uninstall programs for you, based on the receipts folder.  Any true pkg installer should add a receipt to that folder so it can be uninstalled.

I haven't read the previous advice, but basically all you have to do is delete the installed files. Currently that's a little annoying to do, but here's where they are:

/Library/LaunchDaemons/org.jivesoftware.openfire.plist

/usr/local/openfire

/Library/PreferencePanes/Openfire.prefpane