diff --git a/nix.org b/nix.org
index eb6f58c..d053bd3 100644
--- a/nix.org
+++ b/nix.org
@@ -9,97 +9,30 @@
 #+PROPERTY: header-args :comments no
 #+PROPERTY: header-args :replace yes
 
-Nix user config.nix setup.
+TODO: For now macos configuration.nix setup. Will generalize later to nixos too.
 
-#+BEGIN_SRC conf :padline no :mkdirp yes :tangle (tangle/file ".nixpkgs/config.nix" (bound-and-true-p nix-p))
+#+BEGIN_SRC conf :padline no :mkdirp yes :tangle (tangle/file ".nixpkgs/darwin-configuration.nix" (and (bound-and-true-p nix-p) (bound-and-true-p macos-p)))
 {
-  packageOverrides = pkgs: with pkgs;
-  let in rec {
-    # custom-pinentry = pinentry.override { gtk2 = null; ncurses = null; };
-    custom-youtube-dl = python27Packages.youtube-dl.override { pandoc = null; };
+  # List packages installed in system profile. To search by name, run:
+  # $ nix-env -qaP | grep wget
+  environment.systemPackages =
+    [ pkgs.vim
+    ];
 
-    default = buildEnv {
-      name = "default";
-      ignoreCollisions = true;
-      paths = [
-        aria
-        aspell
-        aspellDicts.en
-        cacert
-        clang
-        cloc
-        cscope
-        ctags
-        curl
-        # custom-pinentry
-        custom-youtube-dl
-        diffutils
-        docbook5
-        emacs
-        entr
-        gist
-        gitAndTools.git-extras
-        gitAndTools.gitFull
-        gmp
-        gnumake
-        gnutar
-        gnutls
-        googler
-        graphviz-nox
-        haskellPackages.ShellCheck
-        haskellPackages.pandoc
-        htop
-        imagemagick
-        iperf
-        jq
-        keychain
-        less
-        llvm
-        mercurial
-        moreutils
-        mosh
-        mr
-        ncdu
-        openssl
-        p7zip
-        patchutils
-        pbzip2
-        pkg-config
-        ponysay
-        pv
-        python27Packages.flake8
-        python27Packages.howdoi
-        python27Packages.pip
-        python27Packages.pyflakes
-        python27Packages.pylint
-        python27Packages.virtualenv
-        restic
-        ripgrep
-        rlwrap
-        rsync
-        rtags
-        shfmt
-        silver-searcher
-        sloccount
-        sshpass
-        texlive.combined.scheme-basic
-        tmux
-        transcrypt
-        tree
-        unzip
-        upx
-        wakelan
-        watch
-        wget
-        xz
-        yq
-# If I ever come up with some linux only stuff or figure out xhyve
-#      ] ++ stdenv.lib.optionals stdenv.isLinux [
-#      ] ++ stdenv.lib.optionals stdenv.isDarwin [
-#        xhyve
-      ];
-    };
-  };
-  allowUnfree = true;
+  # Use a custom configuration.nix location.
+  # $ darwin-rebuild switch -I darwin-config=$HOME/.config/nixpkgs/darwin/configuration.nix
+  # environment.darwinConfig = "$HOME/.config/nixpkgs/darwin/configuration.nix";
+
+  # Auto upgrade nix package and the daemon service.
+  # services.nix-daemon.enable = true;
+  # nix.package = pkgs.nix;
+
+  # Create /etc/bashrc that loads the nix-darwin environment.
+  programs.zsh.enable = true;  # default shell on catalina
+  # programs.fish.enable = true;
+
+  # Used for backwards compatibility, please read the changelog before changing.
+  # $ darwin-rebuild changelog
+  system.stateVersion = 4;
 }
 #+END_SRC