diff --git a/.default.nix b/.default.nix
index a49ec1f..14c93a2 100644
--- a/.default.nix
+++ b/.default.nix
@@ -1,19 +1,32 @@
-with import <nixpkgs> {}; {
-  autocmakeEnv = stdenv.mkDerivation {
+let
+  hostPkgs = import <nixpkgs> {};
+  nixpkgs = (hostPkgs.fetchFromGitHub {
+    owner = "NixOS";
+    repo = "nixpkgs-channels";
+    rev = "nixos-unstable";
+    sha256 = "15fcl29a97f68j1pjywmrjm31rdh1a21jz9airlsbzpl4lc3zhfi";
+  });
+in
+  with import nixpkgs {};
+  stdenv.mkDerivation {
     name = "Autocmake";
     buildInputs = [
-      atlas
       ccache
-      clang
       cmake
       doxygen
+      gcc
       gfortran
       liblapack
       openmpi
-      python35Packages.pep8
-      python35Packages.pytest
-      python35Packages.pyyaml
+      pipenv
+      python3Packages.pep8
+      python3Packages.pytest
+      python3Packages.pyyaml
       zlib
     ];
-  };
-}
+    src = null;
+    shellHook = ''
+    export NINJA_STATUS="[Built edge %f of %t in %e sec]"
+    SOURCE_DATE_EPOCH=$(date +%s)
+    '';
+  }
diff --git a/.envrc b/.envrc
index 016678b..44ef8f6 100644
--- a/.envrc
+++ b/.envrc
@@ -1,7 +1 @@
 use nix .default.nix
-export SOURCE_DATE_EPOCH=$(date +%s)
-dir_hash=autocmake-$(echo -n autocmake | shasum | cut -d ' ' -f 1)
-direnv_layout_dir=$XDG_CACHE_HOME/direnv/layouts/$dir_hash
-layout python `type -P python` --system-site-packages
-pip install -r requirements.txt
-export NINJA_STATUS="[Built edge %f of %t in %e sec]"
diff --git a/Pipfile b/Pipfile
new file mode 100644
index 0000000..74ed0aa
--- /dev/null
+++ b/Pipfile
@@ -0,0 +1,16 @@
+[[source]]
+
+url = "https://pypi.python.org/simple"
+verify_ssl = true
+name = "pypi"
+
+
+[packages]
+
+pycodestyle = "*"
+pytest = "*"
+PyYAML = "*"
+
+
+[dev-packages]
+
diff --git a/Pipfile.lock b/Pipfile.lock
new file mode 100644
index 0000000..ea9aea3
--- /dev/null
+++ b/Pipfile.lock
@@ -0,0 +1,92 @@
+{
+    "_meta": {
+        "hash": {
+            "sha256": "256e12866f5cef6ea667f41ee4dcdf970e9c74c1f6e278241746d1c2858472f4"
+        },
+        "host-environment-markers": {
+            "implementation_name": "cpython",
+            "implementation_version": "3.6.4",
+            "os_name": "posix",
+            "platform_machine": "x86_64",
+            "platform_python_implementation": "CPython",
+            "platform_release": "4.9.75",
+            "platform_system": "Linux",
+            "platform_version": "#1-NixOS SMP Fri Jan 5 14:46:36 UTC 2018",
+            "python_full_version": "3.6.4",
+            "python_version": "3.6",
+            "sys_platform": "linux"
+        },
+        "pipfile-spec": 6,
+        "requires": {},
+        "sources": [
+            {
+                "name": "pypi",
+                "url": "https://pypi.python.org/simple",
+                "verify_ssl": true
+            }
+        ]
+    },
+    "default": {
+        "attrs": {
+            "hashes": [
+                "sha256:a17a9573a6f475c99b551c0e0a812707ddda1ec9653bed04c13841404ed6f450",
+                "sha256:1c7960ccfd6a005cd9f7ba884e6316b5e430a3f1a6c37c5f87d8b43f83b54ec9"
+            ],
+            "version": "==17.4.0"
+        },
+        "pluggy": {
+            "hashes": [
+                "sha256:7f8ae7f5bdf75671a718d2daf0a64b7885f74510bcd98b1a0bb420eb9a9d0cff"
+            ],
+            "version": "==0.6.0"
+        },
+        "py": {
+            "hashes": [
+                "sha256:8cca5c229d225f8c1e3085be4fcf306090b00850fefad892f9d96c7b6e2f310f",
+                "sha256:ca18943e28235417756316bfada6cd96b23ce60dd532642690dcfdaba988a76d"
+            ],
+            "version": "==1.5.2"
+        },
+        "pycodestyle": {
+            "hashes": [
+                "sha256:6c4245ade1edfad79c3446fadfc96b0de2759662dc29d07d80a6f27ad1ca6ba9",
+                "sha256:682256a5b318149ca0d2a9185d365d8864a768a28db66a84a2ea946bcc426766"
+            ],
+            "version": "==2.3.1"
+        },
+        "pytest": {
+            "hashes": [
+                "sha256:b84878865558194630c6147f44bdaef27222a9f153bbd4a08908b16bf285e0b1",
+                "sha256:53548280ede7818f4dc2ad96608b9f08ae2cc2ca3874f2ceb6f97e3583f25bc4"
+            ],
+            "version": "==3.3.2"
+        },
+        "pyyaml": {
+            "hashes": [
+                "sha256:3262c96a1ca437e7e4763e2843746588a965426550f3797a79fca9c6199c431f",
+                "sha256:16b20e970597e051997d90dc2cddc713a2876c47e3d92d59ee198700c5427736",
+                "sha256:e863072cdf4c72eebf179342c94e6989c67185842d9997960b3e69290b2fa269",
+                "sha256:bc6bced57f826ca7cb5125a10b23fd0f2fff3b7c4701d64c439a300ce665fff8",
+                "sha256:c01b880ec30b5a6e6aa67b09a2fe3fb30473008c85cd6a67359a1b15ed6d83a4",
+                "sha256:827dc04b8fa7d07c44de11fabbc888e627fa8293b695e0f99cb544fdfa1bf0d1",
+                "sha256:592766c6303207a20efc445587778322d7f73b161bd994f227adaa341ba212ab",
+                "sha256:5f84523c076ad14ff5e6c037fe1c89a7f73a3e04cf0377cb4d017014976433f3",
+                "sha256:0c507b7f74b3d2dd4d1322ec8a94794927305ab4cebbe89cc47fe5e81541e6e8",
+                "sha256:b4c423ab23291d3945ac61346feeb9a0dc4184999ede5e7c43e1ffb975130ae6",
+                "sha256:ca233c64c6e40eaa6c66ef97058cdc80e8d0157a443655baa1b2966e812807ca",
+                "sha256:4474f8ea030b5127225b8894d626bb66c01cda098d47a2b0d3429b6700af9fd8",
+                "sha256:326420cbb492172dec84b0f65c80942de6cedb5233c413dd824483989c000608",
+                "sha256:5ac82e411044fb129bae5cfbeb3ba626acb2af31a8d17d175004b70862a741a7"
+            ],
+            "version": "==3.12"
+        },
+        "six": {
+            "hashes": [
+                "sha256:832dc0e10feb1aa2c68dcc57dbb658f1c7e65b9b61af69048abc87a2db00a0eb",
+                "sha256:70e8a77beed4562e7f14fe23a786b54f6296e34344c23bc42f07b15018ff98e9"
+            ],
+            "version": "==1.11.0"
+        }
+    },
+    "develop": {}
+}
diff --git a/autocmake/generate.py b/autocmake/generate.py
index 244f647..1c26657 100644
--- a/autocmake/generate.py
+++ b/autocmake/generate.py
@@ -45,6 +45,43 @@ def autogenerated_notice():
     return '\n'.join(s)
 
 
+def gen_cmake_options_wrappers():
+    s = """\n# Options handling utilities
+include(CMakeDependentOption)
+# Macro for printing an option in a consistent manner
+# Written by Lori A. Burns (@loriab) and Ryan M. Richard (@ryanmrichard)
+# Syntax: print_option(<option to print> <was specified>)
+macro(print_option variable default)
+  if(NOT DEFINED ${variable} OR "${${variable}}" STREQUAL "")
+    message(STATUS "Setting (unspecified) option ${variable}: ${default}")
+  else()
+    message(STATUS "Setting option ${variable}: ${${variable}}")
+  endif()
+endmacro()
+
+# Wraps an option with default ON/OFF. Adds nice messaging to option()
+# Written by Lori A. Burns (@loriab) and Ryan M. Richard (@ryanmrichard)
+# Syntax: option_with_print(<option name> <description> <default value>)
+macro(option_with_print variable msge default)
+  print_option(${variable} ${default})
+  option(${variable} ${msge} ${default})
+endmacro(option_with_print)
+
+# Wraps an option with a default other than ON/OFF and prints it
+# Written by Lori A. Burns (@loriab) and Ryan M. Richard (@ryanmrichard)
+# NOTE: Can\'t combine with above b/c CMake handles ON/OFF options specially
+# NOTE2: CMake variables are always defined so need to further check for if
+#       they are the NULL string. This is also why weneed the force
+# Syntax: option_with_default(<option name> <description> <default value>)
+macro(option_with_default variable msge default)
+  print_option(${variable} "${default}")
+  if(NOT DEFINED ${variable} OR "${${variable}}" STREQUAL "")
+    set(${variable} "${default}" CACHE STRING ${msge} FORCE)
+  endif()
+endmacro(option_with_default)"""
+    return s
+
+
 def gen_setup(config, default_build_type, relative_path, setup_script_name):
     """
     Generate setup script.
@@ -148,6 +185,8 @@ def gen_cmakelists(project_name, project_language, min_cmake_version, default_bu
     s.append('    set(CMAKE_BUILD_TYPE "{0}")'.format(_build_type))
     s.append('endif()')
 
+    s.append(gen_cmake_options_wrappers())
+
     if len(modules) > 0:
         s.append('\n# directories which hold included cmake modules')
 
diff --git a/modules/math_libs.cmake b/modules/math_libs.cmake
index 0cff139..bd892f2 100644
--- a/modules/math_libs.cmake
+++ b/modules/math_libs.cmake
@@ -46,6 +46,8 @@
 #     - "--blas=<BLAS> Detect and link BLAS library (auto or off) [default: auto]."
 #     - "--lapack=<LAPACK> Detect and link LAPACK library (auto or off) [default: auto]."
 #     - "--mkl=<MKL> Pass MKL flag to the Intel compiler and linker and skip BLAS/LAPACK detection (sequential, parallel, cluster, or off) [default: off]."
+#     - "--scalapack=<SCALAPACK_LIBRARIES> Link line for ScaLAPACK libraries [default: ]"
+#     - "--blacs=<BLACS_IMPLEMENTATION> Implementation of BLACS for MKL ScaLAPACK (openmpi, intelmpi, sgimpt) [default: openmpi]"
 #   define:
 #     - "'-DENABLE_BLAS={0}'.format(arguments['--blas'])"
 #     - "'-DENABLE_LAPACK={0}'.format(arguments['--lapack'])"
@@ -53,8 +55,19 @@
 #     - "'-DMATH_LIB_SEARCH_ORDER=\"MKL;ESSL;OPENBLAS;ATLAS;ACML;SYSTEM_NATIVE\"'"
 #     - "'-DBLAS_LANG=Fortran'"
 #     - "'-DLAPACK_LANG=Fortran'"
+#     - "'-DSCALAPACK_LIBRARIES=\"{0}\"'.format(arguments['--scalapack'])"
+#     - "'-DBLACS_IMPLEMENTATION=\"{0}\"'.format(arguments['--blacs'])"
 #   warning: "the math_libs.cmake module is deprecated and will be removed in future versions"
 
+option_with_default(ENABLE_BLAS "Enable BLAS autodetection" "auto")
+option_with_default(ENABLE_LAPACK "Enable LAPACK autodetection" "auto")
+option_with_default(MKL_FLAG "MKL flag for the Intel compiler and linker. Skips BLAS/LAPACK autodetection" "off")
+option_with_default(MATH_LIB_SEARCH_ORDER "Search order for autodetection of math libraries" "MKL;ESSL;OPENBLAS;ATLAS;ACML;SYSTEM_NATIVE")
+option_with_default(BLAS_LANG "Linker language for BLAS detection" "Fortran")
+option_with_default(LAPACK_LANG "Linker language for LAPACK detection" "Fortran")
+option_with_default(SCALAPACK_LIBRARIES "Link line for ScaLAPACK libraries" "")
+option_with_default(BLACS_IMPLEMENTATION "Implementation of BLACS for MKL ScaLAPACK" "openmpi")
+
 #-------------------------------------------------------------------------------
 # ENABLE_STATIC_LINKING
 
@@ -197,7 +210,7 @@ if(${CMAKE_HOST_SYSTEM_PROCESSOR} STREQUAL "x86_64")
     endif()
 endif()
 
-if(ENABLE_SCALAPACK)
+if(ENABLE_SCALAPACK AND NOT SCALAPACK_LIBRARIES)
     set(_scalapack_lib      mkl_scalapack${_lib_suffix})
     if(${BLACS_IMPLEMENTATION} STREQUAL "intelmpi")
         set(_blacs_lib mkl_blacs_intelmpi${_lib_suffix})
@@ -211,6 +224,7 @@ if(ENABLE_SCALAPACK)
 else()
     set(_scalapack_lib)
     set(_blacs_lib)
+    set(BLACS_IMPLEMENTATION)
 endif()
 
 # MKL 10.0.1.014
@@ -432,7 +446,7 @@ foreach(_service BLAS LAPACK)
     endif()
 endforeach()
 
-if(NOT MKL_FLAG STREQUAL "off")
+if(MKL_FLAG AND NOT MKL_FLAG STREQUAL "off")
     set(EXTERNAL_LIBS ${EXTERNAL_LIBS} -mkl=${MKL_FLAG})
     set(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} -mkl=${MKL_FLAG}")
     message(STATUS "User set explicit MKL flag which is passed to the compiler and linker: -mkl=${MKL_FLAG}")
@@ -495,12 +509,21 @@ foreach(_service BLAS LAPACK)
 endforeach()
 
 # first lapack, then blas as lapack might need blas routine
-set(MATH_LIBS
-    ${MATH_LIBS}
-    ${LAPACK_LIBRARIES}
-    ${BLAS_LIBRARIES}
-    CACHE STRING "Math libraries"
-    )
+if(SCALAPACK_LIBRARIES)
+  list(APPEND MATH_LIBS
+      ${MATH_LIBS}
+      ${SCALAPACK_LIBRARIES}
+      ${LAPACK_LIBRARIES}
+      ${BLAS_LIBRARIES}
+      )
+else()
+  list(APPEND MATH_LIBS
+      ${MATH_LIBS}
+      ${LAPACK_LIBRARIES}
+      ${BLAS_LIBRARIES}
+      )
+endif()
+set(MATH_LIBS ${MATH_LIBS} CACHE STRING "Math libraries")
 
 # further adaptation for the static linking
 if (ENABLE_STATIC_LINKING)
@@ -519,9 +542,3 @@ if (ENABLE_STATIC_LINKING)
         set(MATH_LIBS ${MATH_LIBS} -ldl)
     endif()
 endif()
-
-if(MATH_LIB_SEARCH_ORDER)
-    # this print is here to avoid warning about MATH_LIB_SEARCH_ORDER which
-    # might be set but never used
-    message(STATUS "MATH_LIB_SEARCH_ORDER set to ${MATH_LIB_SEARCH_ORDER}")
-endif()