WEB server hardware?

[ogradyd at us-state.gov]

I'm collecting opinions regarding using Apple servers -- specifically, what is the capacity 
of an Apple Work Group network server in terms of multiple sessions.  Would the Apple 
server be a good choice as the site for a large organization's home page?  The 
concern is housing the site on a server that can handle large numbers of queries 
at the same time.  I'm curious (and obviously rather uninformed on servers) what 
server type is considered to be work-horse quality; suitable say for a large university or 
federal agency.