diff --git a/README.md b/README.md
index 72c7e13..35b52b4 100644
--- a/README.md
+++ b/README.md
@@ -29,6 +29,9 @@ spack install additivefoam
 
 See the [installation instructions](https://ornl.github.io/AdditiveFOAM/docs/installation/#installation) in the [documentation](https://ornl.github.io/AdditiveFOAM/) for other options for building `AdditiveFOAM`.
 
+An alternative installation mechanism is using Nix. See
+[Nix.md](./envs/nix/NIX.md) for more details.
+
 ## Citing
 [![DOI](https://joss.theoj.org/papers/10.21105/joss.07770/status.svg)](https://doi.org/10.21105/joss.07770)
 [![DOI](https://zenodo.org/badge/DOI/10.5281/zenodo.8034097.svg)](https://doi.org/10.5281/zenodo.8034097)
diff --git a/envs/nix/NIX.md b/envs/nix/NIX.md
new file mode 100644
index 0000000..dd7ea59
--- /dev/null
+++ b/envs/nix/NIX.md
@@ -0,0 +1,30 @@
+## Nix
+
+First install the [Nix package manager][NIX] and then enable
+[Flakes][Flakes].  Alternatively, check out the [Determinate Systems
+Installer][Determinate] for an out of the box experience. See
+[nix.dev][nix.dev] for more help with Nix.
+
+To get an environment with both AdditiveFOAM and ExaCA use
+
+    $ nix develop github:ORNL/AdditiveFOAM?dir=envs/nix --accept-flake-config
+    # AdditiveFOAM and ExaCA now available
+    $ additiveFoam --help
+	$ ExaCA --help
+
+To get a specific release, use:
+
+    $ nix develop github:ORNL/AdditiveFOAM/<tag>?dir=envs/nix --accept-flake-config
+
+In principle the build should be fast (on x86-64-linux) as the
+binaries are downloaded from Cachix. You will be prompted to `allow
+configuration setting 'extra-substituters'`.
+
+See the main [README](../../README.md) for more details on building
+AdditiveFOAM.
+
+[NIX]: https://nixos.org/download.html
+[Flakes]: https://nixos.wiki/wiki/Flakes
+[nix.dev]: https://nix.dev
+[Determinate]: https://github.com/DeterminateSystems/nix-installer
+
diff --git a/envs/nix/additivefoam.nix b/envs/nix/additivefoam.nix
new file mode 100644
index 0000000..3f1fed0
--- /dev/null
+++ b/envs/nix/additivefoam.nix
@@ -0,0 +1,106 @@
+{
+  stdenv,
+  makeWrapper,
+  openfoam,
+  openmpi,
+  exaca,
+  src,
+  version,
+  glibc,
+  zlib
+}:
+stdenv.mkDerivation rec {
+  pname = "additivefoam";
+  inherit version;
+  inherit src;
+
+  nativeBuildInputs = [
+    makeWrapper
+  ];
+  
+  buildInputs = [
+    openfoam
+    openmpi
+    zlib
+  ];
+
+  propagatedBuildInputs = [
+    exaca
+    openmpi
+  ];
+  
+  buildPhase = ''
+    runHook preBuild
+
+    mkdir -p builduser/.OpenFOAM
+    mkdir -p builduser/OpenFOAM
+    export HOME=$(pwd)/builduser
+    export USER=builduser
+
+    source ${openfoam.BASHRC} || true
+
+    APPS_DIR=$(pwd)/applications/solvers/additiveFoam
+
+    cd $APPS_DIR/movingHeatSource
+    wmake libso
+
+    cd $APPS_DIR/functionObjects/ExaCA
+    wmake libso
+
+    cd $APPS_DIR
+    wmake
+
+    runHook postBuild
+  '';
+
+  installPhase = ''
+    runHook preInstall
+
+    mkdir -p $out
+
+    cp -r $FOAM_USER_APPBIN $out
+    cp -r $FOAM_USER_LIBBIN $out
+
+    cp -r ${src}/applications $out/
+    cp -r ${src}/tutorials $out/
+
+    runHook postInstall
+  '';
+
+  postInstall = ''
+    wrapProgram $out/bin/additiveFoam \
+      --suffix LD_LIBRARY_PATH : "$out/lib:${openmpi}/lib:${stdenv.cc.cc.lib}/lib:${zlib}/lib"
+
+    LINKER=${glibc}/lib/ld-linux-x86-64.so.2;
+    patchelf --set-interpreter $LINKER $out/bin/.additiveFoam-wrapped
+  '';
+  
+  doCheck = false;
+  doInstallCheck = true;
+
+  installCheckPhase = ''
+
+    cd $HOME
+    mkdir -p app
+    cp -r ${src}/tutorials/AMB2018-02-B/* app/
+    chmod u+w -R app
+    cd app
+
+    # Ensure ExaCA is found
+    substituteInPlace $HOME/app/Allrun --replace-fail "~/install/exaca/bin/ExaCA" "ExaCA"
+    
+    ./Allrun -withExaCA
+
+    if [ -f "ExaCA/Output.vtk" ]; then
+        echo "Check PASSED: Output.vtk generated."
+    else
+        echo "Check FAILED: Output.vtk not found."
+        exit 1 
+    fi
+
+    cd ..
+    rm -rf app
+
+  '';
+  
+}
diff --git a/envs/nix/dev.nix b/envs/nix/dev.nix
new file mode 100644
index 0000000..81a8bd8
--- /dev/null
+++ b/envs/nix/dev.nix
@@ -0,0 +1,41 @@
+{ self', pkgs, lib, ...}:
+
+{
+  devShells = with self'.packages; rec {
+    default = pkgs.mkShell {
+      name = "additivefoam-env";
+
+      packages = [
+        openfoam
+        exaca
+        self'.packages.default
+      ];
+
+      shellHook = ''
+        source ${openfoam.BASHRC}
+      '';                    
+      
+    };
+
+    devel = pkgs.mkShell {
+      name = "additivefoam-dev";
+
+      packages = [
+        openfoam
+        exaca
+      ];
+
+      inputsFrom = [
+        self'.packages.default
+      ];
+
+      shellHook = ''
+        source ${openfoam.BASHRC}
+      '';      
+
+      LOCALE_ARCHIVE = pkgs.lib.optional (pkgs.stdenv.hostPlatform.isLinux) (
+        "${pkgs.glibcLocales}/lib/locale/locale-archive"
+      );
+    };
+  };
+}
diff --git a/envs/nix/flake.lock b/envs/nix/flake.lock
new file mode 100644
index 0000000..8c1626d
--- /dev/null
+++ b/envs/nix/flake.lock
@@ -0,0 +1,132 @@
+{
+  "nodes": {
+    "exaca": {
+      "inputs": {
+        "nixpkgs": "nixpkgs",
+        "parts": "parts"
+      },
+      "locked": {
+        "dir": "envs/nix",
+        "lastModified": 1757080339,
+        "narHash": "sha256-OwphXRWa4v11R81l1gABhzEaeBWtTyi5u6R1Uf1oMhA=",
+        "owner": "LLNL",
+        "repo": "ExaCA",
+        "rev": "562eedc4db2306572ad6dedf6f9e69ea6ecca722",
+        "type": "github"
+      },
+      "original": {
+        "dir": "envs/nix",
+        "owner": "LLNL",
+        "repo": "ExaCA",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1748026580,
+        "narHash": "sha256-rWtXrcIzU5wm/C8F9LWvUfBGu5U5E7cFzPYT1pHIJaQ=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "11cb3517b3af6af300dd6c055aeda73c9bf52c48",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "25.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1753579242,
+        "narHash": "sha256-zvaMGVn14/Zz8hnp4VWT9xVnhc8vuL3TStRqwk22biA=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "0f36c44e01a6129be94e3ade315a5883f0228a6e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib_2": {
+      "locked": {
+        "lastModified": 1753579242,
+        "narHash": "sha256-zvaMGVn14/Zz8hnp4VWT9xVnhc8vuL3TStRqwk22biA=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "0f36c44e01a6129be94e3ade315a5883f0228a6e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
+      "locked": {
+        "lastModified": 1754292888,
+        "narHash": "sha256-1ziydHSiDuSnaiPzCQh1mRFBsM2d2yRX9I+5OPGEmIE=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "ce01daebf8489ba97bd1609d185ea276efdeb121",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-25.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1754487366,
+        "narHash": "sha256-pHYj8gUBapuUzKV/kN/tR3Zvqc7o6gdFB9XKXIp1SQ8=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "af66ad14b28a127c5c0f3bbb298218fc63528a18",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "parts_2": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib_2"
+      },
+      "locked": {
+        "lastModified": 1754487366,
+        "narHash": "sha256-pHYj8gUBapuUzKV/kN/tR3Zvqc7o6gdFB9XKXIp1SQ8=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "af66ad14b28a127c5c0f3bbb298218fc63528a18",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "exaca": "exaca",
+        "nixpkgs": "nixpkgs_2",
+        "parts": "parts_2"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/envs/nix/flake.nix b/envs/nix/flake.nix
new file mode 100644
index 0000000..d34192d
--- /dev/null
+++ b/envs/nix/flake.nix
@@ -0,0 +1,46 @@
+## See NIX.md for help getting started with Nix
+
+{
+  description = "An open-source CFD code for additive manufacturing built on OpenFOAM.";
+
+  nixConfig = {
+    extra-substituters = [ "https://additivefoam.cachix.org" ];
+    extra-trusted-public-keys = [ "additivefoam.cachix.org-1:T65eaaS9ruHWDuAohShjknS95viBv9QTCYcZrCHNXzU=" ];
+  };
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-25.05";
+    exaca.url   = "github:LLNL/ExaCA?dir=envs/nix";
+    parts.url = "github:hercules-ci/flake-parts";
+  };
+
+  outputs = inputs @ { self, parts, ... }: (
+    parts.lib.mkFlake { inherit inputs; } {
+      systems = [
+        "x86_64-linux"
+        "aarch64-linux"
+      ];
+
+      perSystem = { pkgs, inputs', ... }: {
+        packages = rec {
+          default = additivefoam;
+            
+          openfoam = pkgs.callPackage ./openfoam.nix { scotch = scotch; };
+          scotch = pkgs.callPackage ./scotch.nix { };
+          exaca = inputs'.exaca.packages.default;
+
+          additivefoam = pkgs.callPackage ./additivefoam.nix {
+            src = ../..;
+            version = "master";
+            exaca = exaca;
+            openfoam = openfoam;
+          };
+        };
+
+        imports = [
+          ./dev.nix
+        ];
+      };
+    }
+  );
+}
diff --git a/envs/nix/openfoam.nix b/envs/nix/openfoam.nix
new file mode 100644
index 0000000..c657767
--- /dev/null
+++ b/envs/nix/openfoam.nix
@@ -0,0 +1,159 @@
+# Based on this build for OpenFOAM 12
+#   - https://github.com/NixOS/nixpkgs/blob/07ba4b68bad1931618851055077ed20d677b81ed/pkgs/by-name/op/openfoam-org/package.nix
+# Useful as well
+#   - https://git.computecanada.ca/nix/ccpkgs/-/blob/cc-20.09/pkgs/openfoam.nix
+
+{
+  stdenv,
+  bash,
+  m4,
+  flex,
+  bison,
+  fftw,
+  scotch,
+  boost,
+  openmpi,
+  cgal,
+  zlib,
+  fetchFromGitHub,
+  lib,
+  trilinos-mpi
+}:
+let
+  openfoamDrv = stdenv.mkDerivation rec {
+    pname = "openfoam-org";
+    version = "10";
+    src = fetchFromGitHub {
+      owner = "OpenFOAM";
+      repo = "OpenFOAM-12";
+      rev = "refs/tags/version-${version}";
+      hash = "sha256-1vcBZELsThlfSJeW3iFm8sTh+uOgKKEYU0g+XlxczdA=";
+
+    };
+    
+    nativeBuildInputs = [
+      bash
+      flex
+      bison
+    ];
+    
+    
+    buildInputs = [
+      m4
+      fftw
+      boost
+      cgal
+      zlib
+      trilinos-mpi
+      openmpi
+      scotch
+    ];
+
+    propagatedBuildInputs = [
+      openmpi
+    ];
+
+    sourceRoot = ".";
+
+    patchPhase = ''
+    runHook prePatch
+
+    mkdir -p builduser/OpenFOAM
+    mkdir -p builduser/.OpenFOAM
+    export HOME=$(pwd)/builduser
+    export FOAM_DIR=$HOME/OpenFOAM/OpenFOAM-${version}
+    mv source $FOAM_DIR
+    mkdir -p $FOAM_DIR/paraviewout
+    
+    set +e
+    for f in \
+        $FOAM_DIR/wmake/scripts/* \
+        $FOAM_DIR/wmake/*
+    do
+      substituteInPlace $f --replace-quiet /bin/bash ${bash}/bin/bash
+    done
+    set -e
+
+    rm $FOAM_DIR/etc/config.sh/bash_completion
+    touch $FOAM_DIR/etc/config.sh/bash_completion
+
+    echo "set +e" | cat $FOAM_DIR/etc/bashrc > tmp
+    rm $FOAM_DIR/etc/bashrc
+    mv tmp $FOAM_DIR/etc/bashrc
+
+    echo "set +e" | cat $FOAM_DIR/Allwmake > tmp
+    rm $FOAM_DIR/Allwmake
+    mv tmp $FOAM_DIR/Allwmake
+
+    alias wmRefresh="placeholder"
+    chmod +x $FOAM_DIR/Allwmake
+    chmod +x $FOAM_DIR/applications/utilities/postProcessing/graphics/PVReaders/Allwmake
+    touch $HOME/.OpenFOAM/prefs.sh
+
+    # only if version 10
+    substituteInPlace $FOAM_DIR/etc/bashrc --replace-fail "export WM_PROJECT_VERSION=dev" "export WM_PROJECT_VERSION=10"
+    sed -i '47 i libDir=${openmpi.dev}/lib' $FOAM_DIR/etc/config.sh/mpi
+    sed -ie 's|SCOTCH_ARCH_PATH=.*$|SCOTCH_ARCH_PATH=${scotch.dev}|' $FOAM_DIR/etc/config.sh/scotch
+
+    set +e
+    for f in \
+        $FOAM_DIR/src/parallel/decompose/*/Make/options
+    do
+      substituteInPlace $f --replace-quiet /usr/include/scotch ${scotch.dev}/include
+      substituteInPlace $f --replace-quiet "\$(SCOTCH_ARCH_PATH)/lib" ${scotch.out}/lib
+    done
+    set -e
+
+    substituteInPlace $FOAM_DIR/wmake/rules/General/mplibOPENMPI --replace-fail "\$(MPI_ARCH_PATH)/include" "${openmpi.dev}/include"
+    substituteInPlace $FOAM_DIR/wmake/rules/General/mplibOPENMPI --replace-fail "\$(MPI_ARCH_PATH)/lib" "${openmpi.out}/lib"
+
+    # This has a broken link
+    rm $FOAM_DIR/tutorials/mesh/snappyHexMesh/iglooWithFridges
+
+    runHook postPatch
+
+  '';
+
+    buildPhase = ''
+    runHook preBuild
+
+    cd $FOAM_DIR
+    source ./etc/bashrc
+
+    # Can't get it working without these paths.
+    # Shouldn't be required
+    export LD_LIBRARY_PATH="${flex}/lib''${LD_LIBRARY_PATH}"
+    export C_INCLUDE_PATH="${flex}/include''${C_INCLUDE_PATH}"
+    export CPLUS_INCLUDE_PATH="${flex}/include''${CPLUS_INCLUDE_PATH}"
+
+    wmakeLnIncludeAll
+
+    ./Allwmake -j $NIX_BUILD_CORES -q
+
+    runHook postBuild
+  '';
+
+    installPhase = ''
+    runHook preInstall
+
+    FOAM_OUT=$out/opt/OpenFOAM-${version}
+    mkdir -p $FOAM_OUT
+
+    cp -r bin $FOAM_OUT
+    cp -r platforms $FOAM_OUT
+    cp -r etc $FOAM_OUT
+    cp -r applications $FOAM_OUT
+    cp -r src $FOAM_OUT
+    cp -r doc $FOAM_OUT
+    cp -r tutorials $FOAM_OUT
+    cp -r wmake $FOAM_OUT
+
+    runHook postInstall
+  '';
+
+    passthru = {
+      BASHRC = "${openfoamDrv}/opt/OpenFOAM-${version}/etc/bashrc";
+    };
+  };
+in
+  openfoamDrv
diff --git a/envs/nix/scotch.nix b/envs/nix/scotch.nix
new file mode 100644
index 0000000..85106a6
--- /dev/null
+++ b/envs/nix/scotch.nix
@@ -0,0 +1,39 @@
+# Taken from https://github.com/NixOS/nixpkgs/blob/5ee46705af97c806817aa41dbb2914a4bf431ee3/pkgs/by-name/op/openfoam-com/generic.nix
+
+{
+  flex,
+  bison,
+  scotch,
+  zlib,
+  fetchFromGitLab,
+  mpi
+}:
+scotch.overrideAttrs (prev: rec {
+	version = "6.0.9";
+
+  src = fetchFromGitLab {
+    domain = "gitlab.inria.fr";
+    owner = "scotch";
+    repo = "scotch";
+    rev = "v${version}";
+    hash = "sha256-YR2Evj7VnDNGQVNlHovj6CfvPJgAoHeTKu4EW5cXtdg=";
+  };
+
+  nativeBuildInputs = [ ];
+
+  buildInputs = [
+    bison
+    mpi
+    flex
+    zlib
+  ];
+
+  preConfigure = ''
+    cd src
+    ln -s Make.inc/Makefile.inc.x86-64_pc_linux2 Makefile.inc
+  '';
+
+  buildFlags = [ "scotch ptscotch" ];
+
+  installFlags = [ "prefix=\${out}" ];
+})