nfs-kernel-server 1:1.3.4-2.5ubuntu6.1 (amd64 binary) in ubuntu groovy

 The NFS kernel server is currently the recommended NFS server for use
 with Linux, featuring features such as NFSv3 and NFSv4, Kerberos
 support via GSS, and much more. It is also significantly faster and
 usually more reliable than the user-space NFS servers (from the
 unfs3 and nfs-user-server packages). However, it is more difficult to
 debug than the user-space servers, and has a slightly different
 feature set.
 .
 This package contains the user-space support needed to use the
 NFS kernel server. Most administrators wishing to set up an NFS server
 would want to install this package.