Here's how to mount unix file systems onto your OS X Mac. I haven't done nfs exports from the mac to other unix systems, but the link at the bottom for the command-line method should let you figure it out.

For a similar discussion, including more methods, see this HOWTO. Also, this discussion for command-line method.

First, you need to have the administrator of the unix system give your machine permission to mount volumes on that system. You will have very disappointing results otherwise. Also, if you did not set your uid number to that on the unix system (see previous step), you will not have owner privileges for your files on the mounted volume.

Easy way:

For a temporary mount for light-duty work where a stable connection is not needed, you can follow the instructions in AppleCare Document 25344

the Finder uses an unprivileged port to do this, which may not work with some NFS server configurations. Also, is not automatic on rebooting, so you need to re-mount when you reboot.

Harder but more robust way:

This sets up a standard unix nfs mount, which is presumably what you want if you are reading this. Note that you most likely need to run the Repair Privileges utility first.

• Launch netinfo manager and authenticate
• select "mounts"
• from menubar: Directory>New Subdirectory (cmd-n)
• Enter the nfs mount path into the value field (eg tao:/home/tao/salathe. You can find correct root for the volume by typing df on another unix system where the disk is mounted; it is the first column. You can add subdirectories to the path)
• from menubar: Directory->Append property enter "vfstype" in the property field and "nfs" in the value(s) field.
• Append property dir with value of mounting point (eg /tao) this directory must exits
• Append property opts with value -b (to background mount if it fails)
• Append value -P (NFS reserved port assignment)
• Append value -s (soft mount; mount process will fail after a certain number of tries)
• Should have something that looks like:

  Property      Value(s)
  vfstype       nfs
  dir           /tao
  name          tao:/home/tao/salathe
  opts          (-b, -P, -s)
  

• Save and quit
• Now you need to restart the nfs daemons. Find the pids and "kill -HUP" them. From the shell,

  % sudo -s
  % ps -aux | grep -E "nfsiod|automount"
  root      241   0.0  0.0     1276     84  ??  S      0:00.03 nfsiod -n 4
  root      242   0.0  0.0     1276     84  ??  S      0:00.00 nfsiod -n 4
  root      243   0.0  0.0     1276     84  ??  S      0:00.00 nfsiod -n 4
  root      244   0.0  0.0     1276     84  ??  S      0:00.00 nfsiod -n 4
  root      251   0.0  0.1     2392    440  ??  Ss     0:00.08 automount -m /Netwo
  root      413   0.0  0.0     1112    196 std  R+     0:00.00 grep -E nfsiod|auto
  % kill -HUP 241 242 243 244 251 [or whatever the pids]
  

• done!

  Note: Sometimes when the computer goes to sleep and wakes up, mounted volumes are not fully accessible from Finder. They are still there at command line. To fix this, use the "force quit" feature to restart Finder.

You can also do this on the command line.

There is also a shareware gui, NFSManager. I think you need to pay the $17 before it will work.