Netatalk is an open-source software package to deal with the AppleTalk
procotol suite and its relative.  It can do file- and print- sharing for 
macintosh and contains an equivalent of "routed" for the DDP protocol.

It also comes with a load of small utilities to ease dealing with 
Macintosh file from the unix side.

New in 2.0:
 - AFP 3.1
 - large files (>2G) support
 - long file names (up to 255 bytes)