
If you want x11vnc to receive TCP connections from the rest of the world, please add networking.firewall.allowedTCPPorts = [ 5900 ]; to /etc/nixos/configuration.nix. See <http://lists.science.uu.nl/pipermail/nix-dev/2013-November/011997.html> for the discussion that lead to this.
*** NixOS *** NixOS is a Linux distribution based on the purely functional package management system Nix. More information can be found at http://nixos.org/nixos and in the manual in doc/manual.