Netatalk is an OpenSource software package, that can be used to turn an
inexpensive *NIX machine into an extremely high-performance and reliable
file server for Macintosh computers.

Using Netatalk's AFP 3.4 compliant file-server leads to significantly higher
transmission speeds compared with Macs accessing a server via SaMBa/NFS
while providing clients with the best possible user experience (full support
for Macintosh metadata, flawlessly supporting mixed environments of classic
MacOS and MacOS X clients)

WWW: http://netatalk.sourceforge.net/