I manage three Windows PCs at home using the principle of least privilege. This means that practically every other day when a new version of Java is released, I have to manually install the update using my administrative credentials on each machine. This is starting to become more work than I had expected.

I would love to set up an active directory domain at home, but Microsoft has discontinued Windows home server; its replacement, Windows server 2012 essentials is much more expensive (about $500).

Are there any free (preferably as in speech) that would allow me to centrally manage the software installed on each machine in a manner similar to that of active directory? I'd also like to find a way to centrally manage security settings, but I doubt there's an equivalent of group policy.

Samba 4 would be an ideal solution, but according to its own developers, it is not yet stable enough for production use.