Group calendaring with Outlook 2000

I have a group of 6 users who keep individual Outlok calendars. I need to be able to see all of the calendars at one time but coded somehow to tell the different users apart. I found a program that will allow me to do this but it requres Exchange 5.5, which I believe requires Windows 2000 Server to run. All of the machines are currently running Window 98 on a P2P network. I had planned to set up a server for the office but I had hoped to use Red Hat 7.1. Both Windows 2000 server and Red Hat 7.1are new to me. My users do not have to use Outlook but it would be easier.
So, I need to find a way to have group calendaring in a Win 98 environment. Is this possible? Please give details. I hope this is clear.