Samba 4 is the ambitious next version of the Samba suite that is being 
developed in parallel to the stable 3.0 series. The main emphasis in 
this branch is full support for being a Active Directory domain controller.

Samba 4 is currently not yet in a state where it is usable in production 
environments. The STATUS file aims to document what should and should not 
work.

Those familiar with Samba 3 can find a list of user-visible changes 
since that release series in the NEWS file. A short guide to setting up 
Samba 4 can be found in the howto.txt file in this directory.

Bugs can be filed at https://bugzilla.samba.org/. Please
look at the STATUS file before filing a bug to see if a particular 
is supposed to work yet.

Development and general discussion about Samba 4 happens mainly on 
the #samba-technical IRC channel (on irc.freenode.net) and 
the samba-technical mailing list (see http://lists.samba.org/ for 
details).