diff --git a/.github/workflows/deploy_api_docs.yml.OFF b/.github/workflows/deploy_api_docs.yml.OFF
new file mode 100755
index 0000000..a5556a3
--- /dev/null
+++ b/.github/workflows/deploy_api_docs.yml.OFF
@@ -0,0 +1,46 @@
+#name: Build FORD docs & deploy to gh-pages
+name: FORD docs deployed to main
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  build:
+    name: Deploy docs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Python
+        uses: actions/setup-python@v2
+        with:
+          python-version: '3.x'
+
+      - name: Install dependencies
+        run: python -m pip install --upgrade pip ford
+
+      - name: Checkout main
+        uses: actions/checkout@v1
+
+      - name: Build docs
+        run: |
+              ford --version
+              ford ford.md
+              ls
+              tree
+
+      - name: Deploy
+        uses: JamesIves/github-pages-deploy-action@releases/v3
+        with:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          #BRANCH: gh_pages
+          BRANCH: main
+          FOLDER: docs/fpm-ford
+          TARGET_FOLDER: docs/fpm-ford
+#         ford(1) deletes the output directory before running
+#         so be careful to specify a unique subdirectory in
+#         your ford(1) configuration files
+
+# valid inputs are ['SSH', 'ACCESS_TOKEN', 'GITHUB_TOKEN', 'BRANCH',
+# 'FOLDER', 'TARGET_FOLDER', 'BASE_BRANCH', 'COMMIT_MESSAGE', 'CLEAN',
+# 'CLEAN_EXCLUDE', 'GIT_CONFIG_NAME', 'GIT_CONFIG_EMAIL', 'REPOSITORY_NAME',
+# 'WORKSPACE', 'SINGLE_COMMIT', 'LFS', 'SILENT', 'PRESERVE']
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
new file mode 100755
index 0000000..712c821
--- /dev/null
+++ b/.github/workflows/docs.yml
@@ -0,0 +1,23 @@
+name: FORD docs deployed to gh-pages
+
+on: [push, pull_request]
+
+jobs:
+  build-and-deploy:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+    - uses: actions/setup-python@v1
+      with:
+        python-version: '3.x'
+    - name: Install dependencies
+      run: pip install ford
+    - name: Build Documentation
+      run: ford ford.md
+    - uses: JamesIves/github-pages-deploy-action@3.7.1
+      if: github.event_name == 'push'
+      with:
+        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        BRANCH: gh-pages
+        FOLDER: docs/fpm-ford
+        CLEAN: true
diff --git a/.github/workflows/test_gfortran_macos.yml.OFF b/.github/workflows/test_gfortran_macos.yml.OFF
new file mode 100755
index 0000000..811d852
--- /dev/null
+++ b/.github/workflows/test_gfortran_macos.yml.OFF
@@ -0,0 +1,110 @@
+name: macos with gfortran
+
+on: [push, pull_request]
+
+jobs:
+  Build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ macos-latest ]
+        include:
+        - os: macos-latest
+          gcc_v: 12
+    env:
+      FC: gfortran
+      GCC_V: ${{ matrix.gcc_v }}
+      TZ: UTC+04:00
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+
+    - name: Install GFortran macOS
+      run: |
+          ls /usr/local/bin/gfortran-*
+          ln -f -s /usr/local/bin/gfortran-${GCC_V} /usr/local/bin/gfortran
+          which gfortran-${GCC_V}
+          which gfortran
+          ## Alternative:
+          #conda create -n gf gfortran
+          #conda activate gf
+
+    - name: Install fpm
+      run: |
+           echo $PATH
+           pwd
+           uname -a
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+           mkdir -p /Users/runner/bin tmp
+           ulimit -c unlimited -d unlimited -f unlimited -m unlimited -t unlimited -v unlimited
+           gfortran fpm.F90 -Jtmp -Itmp -o /Users/runner/bin/fpm
+           rm -f tmp/*.mod
+           ls -l
+
+    - name: Display environment
+      run: |
+        echo $PATH
+        pwd
+        uname -a
+        ulimit -a
+        echo "end" > foo.f90
+        gfortran -cpp -E -dM foo.f90
+        gfortran --version
+        fpm --version
+        ulimit -a
+
+    - name: tests MacOS (release)
+      run: |
+          ulimit -c unlimited -d unlimited -f unlimited -m unlimited -t unlimited -v unlimited
+          exec 2>&1
+          set -x
+          #fpm test --profile release --verbose --flag -fno-automatic        # looks like bug where formats go on stack anyway
+          #fpm test --profile debug --verbose --flag -fmax-stack-var-size=0  # Apparently infinite loop
+          #fpm test --profile debug --verbose --flag -fmax-stack-var-size=2024 # loop
+          #fpm test --profile debug --verbose --flag -frecursive
+          #fpm test --profile debug --verbose --flag -static
+          #timeout 0.5h fpm test --profile debug --verbose
+          ulimit -S -t 1800
+          fpm test --profile debug --verbose
+
+    - name: tests MacOS (debug)
+      run: |
+          ulimit -c unlimited -d unlimited -f unlimited -m unlimited -t unlimited -v unlimited
+          exec 2>&1
+          set -x
+          ulimit -S -t 1800
+          fpm test --profile debug --verbose
+
+    - name: cleanup MacOS
+      run: ls -ltras
+#       -fno-automatic
+#     Treat each program unit (except those marked as RECURSIVE) as if
+#     the "SAVE" statement were specified for every local variable and
+#     array referenced in it. Does not affect common blocks. (Some
+#     Fortran compilers provide this option under the name -static or
+#     -save.)  The default, which is -fautomatic, uses the stack for
+#     local variables smaller than the value given by
+#     -fmax-stack-var-size.  Use the option -frecursive to use no static
+#     memory.
+#
+#     Local variables or arrays having an explicit "SAVE" attribute are
+#     silently ignored unless the -pedantic option is added.
+# -fmax-stack-var-size=n
+#     This option specifies the size in bytes of the largest array that
+#     will be put on the stack; if the size is exceeded static memory is
+#     used (except in procedures marked as RECURSIVE). Use the option
+#     -frecursive to allow for recursive procedures which do not have a
+#     RECURSIVE attribute or for parallel programs. Use -fno-automatic to
+#     never use the stack.
+#
+#     This option currently only affects local arrays declared with
+#     constant bounds, and may not apply to all character variables.
+#     Future versions of GNU Fortran may improve this behavior.
+#
+#     The default value for n is 32768.
+# -frecursive
+#     Allow indirect recursion by forcing all local arrays to be
+#     allocated on the stack. This flag cannot be used together with
+#     -fmax-stack-var-size= or -fno-automatic.
diff --git a/.github/workflows/test_gfortran_mingw64_windows.yml.OFF b/.github/workflows/test_gfortran_mingw64_windows.yml.OFF
new file mode 100755
index 0000000..1bb0895
--- /dev/null
+++ b/.github/workflows/test_gfortran_mingw64_windows.yml.OFF
@@ -0,0 +1,74 @@
+name: windows mingw64 with gfortran
+
+on: [push, pull_request]
+
+env:
+  CTEST_TIME_TIMEOUT: "50"  # some failures hang forever
+
+jobs:
+  build:
+    runs-on: windows-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        include: [
+          { msystem: MINGW64, arch: x86_64 },
+        ]
+    env:
+      FC: gfortran
+      TZ: UTC+04:00
+    defaults:
+      run:
+        shell: msys2 {0}
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Setup MinGW native environment
+      uses: msys2/setup-msys2@v2
+      if: contains(matrix.msystem, 'MINGW')
+      with:
+        msystem: ${{ matrix.msystem }}
+        update: false
+        install: >-
+          git
+          wget
+          mingw-w64-${{ matrix.arch }}-gcc
+          mingw-w64-${{ matrix.arch }}-gcc-fortran
+
+    - name: Install fpm
+      run: |
+           echo $PATH
+           pwd
+           uname -a
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+           mkdir -p tmp
+           gfortran fpm.F90 -Jtmp -Itmp -static -o fpm
+           rm -f tmp/*.mod
+           ls -l
+
+    - name: tests (release)
+      run: |
+        gfortran --version
+        PATH=$PATH:.
+        ./fpm test --compiler gfortran --profile release -flag "-D _WIN32"
+      env:
+        FPM_COMPILER: gfortran
+        CC: gcc
+        CXX: g++
+        FC: gfortran
+        TZ: UTC+04:00
+
+    - name: tests (debug)
+      run: |
+        PATH=$PATH:.
+        gfortran --version
+        ./fpm test --compiler gfortran --profile debug   -flag "-D _WIN32"
+      env:
+        FPM_COMPILER: gfortran
+        CC: gcc
+        CXX: g++
+        FC: gfortran
+        TZ: UTC+04:00
+
+    - name: cleanup 
+      run: ls -ltras
diff --git a/.github/workflows/test_gfortran_msys_meson_windows.yml.WIP.OFF b/.github/workflows/test_gfortran_msys_meson_windows.yml.WIP.OFF
new file mode 100755
index 0000000..204817a
--- /dev/null
+++ b/.github/workflows/test_gfortran_msys_meson_windows.yml.WIP.OFF
@@ -0,0 +1,65 @@
+name: msys windows gfortran
+
+on: [push, pull_request]
+
+env:
+  CTEST_TIME_TIMEOUT: "5"  # some failures hang forever
+  FC: gfortran
+  TZ: UTC+04:00
+
+jobs:
+  gfortran-windows-msys2-mingw64:
+    runs-on: windows-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+
+    - name: Setup MinGW (MSYS2)
+      uses: msys2/setup-msys2@v2
+      with:
+        msystem: MINGW64
+        update: false
+        install: >-
+          git
+          wget
+          mingw-w64-x86_64-gcc-fortran
+          mingw-w64-x86_64-meson
+          mingw-w64-x86_64-ninja
+
+    - name: Install fpm
+      shell: msys2 {0}
+      run: |
+           echo $PATH
+           pwd
+           uname -a
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+	   mkdir tmp
+           gfortran fpm.F90 -Itmp -Jtmp -o fpm
+
+    - name: Run tests and demo programs (debug)
+      shell: msys2 {0}
+      run: |
+        gfortran --version
+        ./fpm test --profile release -flag "-D _WIN32"
+      env:
+         FC: gfortran
+         TZ: UTC+04:00
+
+    - name: Run tests and demo programs (release)
+      shell: msys2 {0}
+      run: |
+        gfortran --version
+        ./fpm test --profile release -flag "-D _WIN32"
+      env:
+         FC: gfortran
+         TZ: UTC+04:00
+
+    - name: Build with meson
+      shell: msys2 {0}
+      run: |
+        meson --version
+        meson setup build -Dbuildtype=debug
+        meson compile -C build
+
+    - name: cleanup 
+      run: dir
diff --git a/.github/workflows/test_gfortran_msys_windows.yml.OFF b/.github/workflows/test_gfortran_msys_windows.yml.OFF
new file mode 100755
index 0000000..e276909
--- /dev/null
+++ b/.github/workflows/test_gfortran_msys_windows.yml.OFF
@@ -0,0 +1,54 @@
+name: msys windows gfortran
+
+on: [push, pull_request]
+
+env:
+  CTEST_TIME_TIMEOUT: "5"  # some failures hang forever
+  FC: gfortran
+  TZ: UTC+04:00
+
+jobs:
+  gfortran-windows-msys2-mingw64:
+    runs-on: windows-latest
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+
+    - name: Setup MinGW (MSYS2)
+      uses: msys2/setup-msys2@v2
+      with:
+        msystem: MINGW64
+        update: false
+        install: >-
+          git
+          wget
+          mingw-w64-x86_64-gcc-fortran
+
+    - name: Install fpm
+      shell: msys2 {0}
+      run: |
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+           mkdir tmp
+           gfortran fpm.F90 -Jtmp -Itmp -static -o fpm
+           rm -f tmp/*.mod
+
+    - name: Run tests and demo programs (debug)
+      shell: msys2 {0}
+      run: |
+        gfortran --version
+        ./fpm test --profile release -flag "-D _WIN32"
+      env:
+         FC: gfortran
+         TZ: UTC+04:00
+
+    - name: Run tests and demo programs (release)
+      shell: msys2 {0}
+      run: |
+        gfortran --version
+        ./fpm test --profile release -flag "-D _WIN32"
+      env:
+         FC: gfortran
+         TZ: UTC+04:00
+
+    - name: cleanup 
+      run: dir
diff --git a/.github/workflows/test_gfortran_ubuntu.yml.OFF b/.github/workflows/test_gfortran_ubuntu.yml.OFF
new file mode 100755
index 0000000..9188dea
--- /dev/null
+++ b/.github/workflows/test_gfortran_ubuntu.yml.OFF
@@ -0,0 +1,66 @@
+name: ubuntu with gfortran
+
+on: [push, pull_request]
+
+jobs:
+  Build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest ]
+        include:
+        - os: ubuntu-latest
+          gcc_v: 12
+
+    env:
+      FC: gfortran
+      GCC_V: ${{ matrix.gcc_v }}
+      TZ: UTC+04:00
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+
+    - name: Install GFortran Linux
+      run: |
+        sudo update-alternatives --install /usr/bin/gcc gcc /usr/bin/gcc-${GCC_V} 100 \
+        --slave /usr/bin/gfortran gfortran /usr/bin/gfortran-${GCC_V} \
+        --slave /usr/bingcov gcov /usr/bin/gcov-${GCC_V}
+
+    - name: Install fpm
+      run: |
+           echo $PATH
+           pwd
+           uname -a
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+           mkdir -p /home/runner/.local/bin tmp
+           ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+           gfortran fpm.F90 -Itmp -Jtmp -static -o /home/runner/.local/bin/fpm
+           rm -f tmp/*.mod
+           ls -l
+
+    - name: Display environment
+      run: |
+        #make -k -p -fNOTTHERE
+        echo "end" > foo.f90
+        ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+        gfortran -cpp -E -dM foo.f90
+        gfortran --version
+        fpm --version
+
+    - name: ubuntu with gfortran (debug)
+      run: |
+           ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+           fpm test --profile debug --verbose
+
+    - name: ubuntu with gfortran (release)
+      run: |
+           ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+           fpm test --profile release 
+
+#    - name: Run demo programs (fpm run)
+#      run: fpm run --profile release
+
+    - name: cleanup Linux
+      run: ls -ltras
diff --git a/.github/workflows/test_gfortran_windows.yml.OFF b/.github/workflows/test_gfortran_windows.yml.OFF
new file mode 100755
index 0000000..e8765e9
--- /dev/null
+++ b/.github/workflows/test_gfortran_windows.yml.OFF
@@ -0,0 +1,66 @@
+name: windows with gfortran
+
+on: [push, pull_request]
+
+jobs:
+  Build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [windows-latest]
+        gcc_v: [10] # Version of GFortran we want to use.
+        include:
+
+        - os: windows-latest
+          os-arch: windows-x86_64
+          release-flags: --flag '--static -g -fbacktrace -O3'
+          exe: .exe
+
+    env:
+      FC: gfortran
+      GCC_V: ${{ matrix.gcc_v }}
+      TZ: UTC+04:00
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v1
+
+    - name: Install fpm
+      run: |
+           echo PATH %PATH%
+           pwd
+           curl https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90 --output fpm.F90
+           mkdir tmp
+           gfortran -static fpm.F90 -Itmp -Jtmp -o fpm -D_WIN32 2>&1
+           dir
+      shell: cmd
+
+    - name: Display environment
+      run: |
+        echo PATH %PATH%
+        pwd
+        uname -a
+        echo "end" > foo.f90
+        gfortran -cpp -E -dM foo.f90
+        fpm --version
+        fpm build --verbose
+        gfortran --version
+      shell: cmd
+
+    - name: tests MSWindows (debug)
+      run: |
+              fpm test --profile debug -flag "-static -D _WIN32" --verbose 2>&1
+      shell: cmd
+
+    - name: tests MSWindows (release)
+      run: |
+              fpm test --profile release -flag "-static -D _WIN32" --verbose 2>&1
+      shell: cmd
+
+    - name: cleanup MSWindows
+      run: dir
+      shell: cmd
+
+#set PATH=%PATH%;%CD%
+#make -k -p -fNOTTHERE
diff --git a/.github/workflows/test_ifx_ubuntu.yml.OFF b/.github/workflows/test_ifx_ubuntu.yml.OFF
new file mode 100755
index 0000000..70b74c6
--- /dev/null
+++ b/.github/workflows/test_ifx_ubuntu.yml.OFF
@@ -0,0 +1,70 @@
+name: linux with intel ifx compiler
+
+on: [push, pull_request]
+
+jobs:
+  # Build with Intel ifx toolchain
+  intel-build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-20.04]
+        fc: [ifx]
+        cc: [icc]
+
+    env:
+      FC: ${{ matrix.fc }}
+      CC: ${{ matrix.cc }}
+      FPM_COMPILER: ifx
+      TZ: UTC+04:00
+      APT_PACKAGES: >-
+        intel-oneapi-compiler-fortran
+        intel-oneapi-compiler-dpcpp-cpp-and-cpp
+        intel-oneapi-mkl-devel
+        asciidoctor
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - uses: actions/setup-python@v1
+      with:
+        python-version: '3.x'
+
+    - name: Add Intel repository
+      run: |
+        wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        rm GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        echo "deb https://apt.repos.intel.com/oneapi all main" | sudo tee /etc/apt/sources.list.d/oneAPI.list
+        sudo apt-get update
+
+    - name: Install Intel oneAPI compiler
+      run: |
+        sudo apt-get install ${{ env.APT_PACKAGES }}
+        source /opt/intel/oneapi/setvars.sh
+        printenv >> $GITHUB_ENV
+
+    - name: Install fpm
+      run: |
+           echo $PATH
+           pwd
+           uname -a
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+           mkdir -p /home/runner/.local/bin tmp
+           ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+           ifx fpm.F90 -Itmp -module tmp -o /home/runner/.local/bin/fpm
+           ls -l
+           rm -fv *.mod tmp/*.mod
+
+    - name: Run Intel unit tests on Linux
+      run: |
+        printenv TZ
+        printenv FPM_COMPILER
+        printenv OMP_NUM_THREADS
+        ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+        fpm test --profile release --compiler ifx
+        ls -l
+      env:
+        OMP_NUM_THREADS: 2,1
diff --git a/.github/workflows/test_intel_ubuntu.yml b/.github/workflows/test_intel_ubuntu.yml
new file mode 100755
index 0000000..42a27a1
--- /dev/null
+++ b/.github/workflows/test_intel_ubuntu.yml
@@ -0,0 +1,70 @@
+name: linux with intel
+
+on: [push, pull_request]
+
+jobs:
+  # Build with Intel toolchain
+  intel-build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-20.04]
+        fc: [ifort]
+        cc: [icc]
+
+    env:
+      FC: ${{ matrix.fc }}
+      CC: ${{ matrix.cc }}
+      FPM_COMPILER: ifort
+      TZ: UTC+04:00
+      APT_PACKAGES: >-
+        intel-oneapi-compiler-fortran
+        intel-oneapi-compiler-dpcpp-cpp-and-cpp-classic
+        intel-oneapi-mkl-devel
+        asciidoctor
+
+    steps:
+    - name: Checkout code
+      uses: actions/checkout@v2
+
+    - uses: actions/setup-python@v1
+      with:
+        python-version: '3.x'
+
+    - name: Add Intel repository
+      run: |
+        wget https://apt.repos.intel.com/intel-gpg-keys/GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        sudo apt-key add GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        rm GPG-PUB-KEY-INTEL-SW-PRODUCTS-2023.PUB
+        echo "deb https://apt.repos.intel.com/oneapi all main" | sudo tee /etc/apt/sources.list.d/oneAPI.list
+        sudo apt-get update
+
+    - name: Install Intel oneAPI compiler
+      run: |
+        sudo apt-get install ${{ env.APT_PACKAGES }}
+        source /opt/intel/oneapi/setvars.sh
+        printenv >> $GITHUB_ENV
+
+    - name: Install fpm
+      run: |
+           echo $PATH
+           pwd
+           uname -a
+           wget https://raw.githubusercontent.com/urbanjost/index/main/bootstrap/fpm.F90
+           mkdir -p /home/runner/.local/bin tmp
+           ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+           ifort fpm.F90 -Itmp -module tmp -o /home/runner/.local/bin/fpm
+           ls -l
+           rm -fv *.mod tmp/*.mod
+
+    - name: Run Intel unit tests on Linux
+      run: |
+        printenv TZ
+        printenv FPM_COMPILER
+        printenv OMP_NUM_THREADS
+        ulimit -c unlimited -d unlimited -f unlimited -m unlimited -s unlimited -t unlimited -v unlimited -x unlimited
+        fpm test --profile release --compiler ifort
+        ls -l
+      env:
+        OMP_NUM_THREADS: 2,1
diff --git a/.gitignore b/.gitignore
new file mode 100755
index 0000000..a05c5dd
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,3 @@
+build/*
+docs/fpm-ford
+docs/doxygen_out
diff --git a/GNUmakefile b/GNUmakefile
index 6daea38..b40cf0b 100644
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -9,10 +9,10 @@ F:= ifort
 SRC := rpn_stack.f90 rpn_stack_sm.f90 linked_list.f90 amap.f90
 OBJ := $(SRC:%.f90=%.o)
 
-hp: hp.f90 $(OBJ)
-	$(F) -o $@ hp.f90 $(OBJ) $(F_OPTS)
+hp: ../app/main.f90 $(OBJ)
+	$(F) -o $@ ../app/main.f90 $(OBJ) $(F_OPTS)
 
-hp.exe: hp.f90 GNUmakefile
+hp.exe: /app/main.f90 GNUmakefile
 	$(F) -o $@ $< $(F_OPTS)
 	
 rpn_stack_sm.o: rpn_stack_sm.f90
@@ -27,8 +27,8 @@ linked_list.o: linked_list.f90
 amap.o: amap.f90
 	$(F) -c -o $@ $< $(F_OPTS)
 
-test_amap: test_amap.f90 amap.o
-	$(F) -o $@ test_amap.f90 amap.o
+test_amap: ../test/test_amap.f90 amap.o
+	$(F) -o $@ ../test/test_amap.f90 amap.o
 
 clean:
 	@rm -vf *.o *.mod *.smod *~
@@ -41,8 +41,8 @@ force: veryclean
 
 export: hp.tar
 
-hp.tar: GNUmakefile hp.f90 $(SRC)
-	tar cf $@ hp.f90 $(SRC) GNUmakefile
+hp.tar: GNUmakefile ../app/hp.f90 $(SRC)
+	tar cf $@ ../app/hp.f90 $(SRC) GNUmakefile
 
 help:
 	@echo "SRC = $(SRC)"
diff --git a/README.md b/README.md
index 52abf91..4184612 100644
--- a/README.md
+++ b/README.md
@@ -44,3 +44,23 @@ Examples
     hp "2 -- complex sqrt ="                      -> (0.00000,-1.414214)
     hp -c "radians (1,pi_over_2)p ^ * degrees ="  -> (1.000000,180.000000) p
 ```
+
+## Build and Test with FPM
+
+   To build with fpm(1) 
+   ( as described at [Fortran Package Manager](https://github.com/fortran-lang/fpm) )
+   enter:
+
+   ```bash
+        git clone https://github.com/sgeard/hp.git
+        cd hp
+        fpm test
+        fpm run 
+   ```
+
+   or just list it as a dependency in your fpm.toml project file.
+
+```toml
+        [dependencies]
+        hp        = { git = "https://github.com/sgeard/hp.git" }
+```
diff --git a/hp.f90 b/app/main.f90
similarity index 100%
rename from hp.f90
rename to app/main.f90
diff --git a/docs/images/favicon.ico b/docs/images/favicon.ico
new file mode 100644
index 0000000..2754147
Binary files /dev/null and b/docs/images/favicon.ico differ
diff --git a/ford.md b/ford.md
new file mode 100755
index 0000000..a9d570b
--- /dev/null
+++ b/ford.md
@@ -0,0 +1,31 @@
+---
+src_dir: src
+         app
+         example
+         test
+output_dir: docs/fpm-ford
+project: hp
+summary: RPN calculator in modern Fortran
+project_github: https://github.com/sgeard/hp
+project_download:
+author: sgeard
+author_email: sgeard@gmail.com
+github: https://github.com/sgeard/hp
+media_dir: docs/images
+exclude_dir: archive
+             FODDER
+display: public
+         protected
+source: true
+proc_internals: true
+sort: permission-alpha
+favicon: docs/images/favicon.ico
+print_creation_date: true
+extra_mods: iso_fortran_env:https://gcc.gnu.org/onlinedocs/gfortran/ISO_005fFORTRAN_005fENV.html
+            tomlf:https://toml-f.github.io/toml-f
+creation_date: %Y-%m-%d %H:%M %z
+md_extensions: markdown.extensions.toc
+               markdown.extensions.smarty
+---
+
+{!README.md!}
diff --git a/fpm.toml b/fpm.toml
new file mode 100644
index 0000000..caab095
--- /dev/null
+++ b/fpm.toml
@@ -0,0 +1,21 @@
+name = "hp"
+version = "0.1.0"
+license = "license"
+author = "sgeard"
+maintainer = "sgeard@gmail.com"
+copyright = "Copyright 2023, sgeard"
+
+[build]
+   auto-executables = true
+   auto-tests = true
+   auto-examples = true
+   module-naming = false
+
+[install]
+   library = false
+
+[fortran]
+   implicit-typing = false
+   implicit-external = false
+   source-form = "free"
+
diff --git a/src/GNUmakefile b/src/GNUmakefile
new file mode 100644
index 0000000..b40cf0b
--- /dev/null
+++ b/src/GNUmakefile
@@ -0,0 +1,49 @@
+.PHONY: veryclean clean force export help
+
+ifdef debug
+F_OPTS := -ggdb
+endif
+
+F:= ifort
+
+SRC := rpn_stack.f90 rpn_stack_sm.f90 linked_list.f90 amap.f90
+OBJ := $(SRC:%.f90=%.o)
+
+hp: ../app/main.f90 $(OBJ)
+	$(F) -o $@ ../app/main.f90 $(OBJ) $(F_OPTS)
+
+hp.exe: /app/main.f90 GNUmakefile
+	$(F) -o $@ $< $(F_OPTS)
+	
+rpn_stack_sm.o: rpn_stack_sm.f90
+	$(F) -c -o $@ $< $(F_OPTS)
+	
+rpn_stack.o: rpn_stack.f90
+	$(F) -c -o $@ $< $(F_OPTS)
+
+linked_list.o: linked_list.f90
+	$(F) -c -o $@ $< $(F_OPTS)
+
+amap.o: amap.f90
+	$(F) -c -o $@ $< $(F_OPTS)
+
+test_amap: ../test/test_amap.f90 amap.o
+	$(F) -o $@ ../test/test_amap.f90 amap.o
+
+clean:
+	@rm -vf *.o *.mod *.smod *~
+
+veryclean: clean
+	@rm -vf hp hp.exe hp.tar
+
+force: veryclean
+	$(MAKE)
+
+export: hp.tar
+
+hp.tar: GNUmakefile ../app/hp.f90 $(SRC)
+	tar cf $@ ../app/hp.f90 $(SRC) GNUmakefile
+
+help:
+	@echo "SRC = $(SRC)"
+	@echo "OBJ = $(OBJ)"
diff --git a/amap.f90 b/src/amap.f90
similarity index 99%
rename from amap.f90
rename to src/amap.f90
index 4732a4e..d9e47ca 100644
--- a/amap.f90
+++ b/src/amap.f90
@@ -177,7 +177,7 @@ contains
         integer, intent(out)        :: iostat
         character(*), intent(inout) :: iomsg
         iostat = 0
-        iomsg = ""
+        !iomsg = ""
         write(6,'(a)', iostat=iostat, iomsg=iomsg) trim(adjustl(key%k))
     end subroutine write_key_t
 
@@ -189,7 +189,7 @@ contains
         integer, intent(out)        :: iostat
         character(*), intent(inout) :: iomsg
         iostat = 0
-        iomsg = ""
+        !iomsg = ""
         write(6,'(f0.6)', iostat=iostat, iomsg=iomsg) value%v
     end subroutine write_value_t
 end module amap
diff --git a/linked_list.f90 b/src/linked_list.f90
similarity index 100%
rename from linked_list.f90
rename to src/linked_list.f90
diff --git a/rpn_stack.f90 b/src/rpn_stack.f90
similarity index 100%
rename from rpn_stack.f90
rename to src/rpn_stack.f90
diff --git a/rpn_stack_sm.f90 b/src/rpn_stack_sm.f90
similarity index 99%
rename from rpn_stack_sm.f90
rename to src/rpn_stack_sm.f90
index a830576..20772d5 100644
--- a/rpn_stack_sm.f90
+++ b/src/rpn_stack_sm.f90
@@ -153,7 +153,7 @@ contains
         complex(8) :: z
         character(len=:), allocatable :: str_re, str_im
         iostat = 0
-        iomsg = ""
+        !iomsg = ""
         z = se%zdata
         if (complex_mode) then
             call to_string(z%re,str_re)
diff --git a/test_amap.f90 b/test/test_amap.f90
similarity index 100%
rename from test_amap.f90
rename to test/test_amap.f90