Mac Server

I am a Videographer/editor for a local school district, and was wondering if I could set up a Mac g5 as a server without the MAC OS X Server software. is there an option that will enable me to use the g5 right out of the box as a server? or will I have to purchase the server software for my mac? I wanted to set up one as a file server so that the other two macs could access video, logs, etc in final cut pro. Any suggestions would be appreciated. Thank you.

OS X is easily able to function as a server and share files. OS X server is only necessary to function as a huge, full-fledged server. If you're just using it to act as a simple file server between a few machines, you should have no problem.