Exemple setup for linux:
directory shared : /home/true_atlantis
true_atlantis uid : 500
true_atlantis gid :100
macintosh IP : 10.0.0.10
linux IP: 10.0.0.12
edit /etc/exports :
/home/true_atlantis 10.0.0.10(sync,rw,anonuid=500,anongid=100,insecure)
then restart NFS server (if /etc/rc.d/rc.nfsd is not executable, chmod +x it and also /etc/rc.d/rc.portmap too) :
/etc/rc.d/rc.nfsd restart
Now on the mac, from the Finder do [command + K] (where 'command' is the apple key)
Then type :
nfs://10.0.0.12/home/true_atlantis
And voila
look at your desktop, there should be an icon wich is the linux shared directory mounted.