diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1094098..ecf5f9f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,20 +5,22 @@ project(CosmoToolbox)
 
 include(GetGitRevisionDescription)
 include(ExternalProject)
-include(FindOpenMP)
+include(FindPkgConfig)
+include(FindPackageHandleStandardArgs)
 
 include(FindPythonInterp)
 set(NumPy_FIND_REQUIRED TRUE)
 include(${CMAKE_SOURCE_DIR}/FindPyLibs.cmake)
 include(${CMAKE_SOURCE_DIR}/FindNumPy.cmake)
 
-
 get_git_head_revision(HEAD GIT_VER)
 
 option(BUILD_SHARED_LIBS "Build shared libraries." OFF)
 option(BUILD_STATIC_LIBS "Build static libraries." ON)
-option(ENABLE_OPENMP "Enable OpenMP support." OFF)
-option(ENABLE_SHARP "Enable SPHT support." ON)
+option(ENABLE_SHARP "Enable SHARP support." ON)
+option(INTERNAL_HDF5 "Build internal version of HDF5" OFF)
+option(INTERNAL_NETCDF "Build internal version of NETCDF" OFF)
+option(INTERNAL_BOOST "Build internal version of BOOST" OFF)
 
 IF(BUILD_SHARED_LIBS AND BUILD_STATIC_LIBS)
   SET(CosmoTool_local CosmoTool_static)
@@ -26,10 +28,7 @@ ELSE(BUILD_SHARED_LIBS AND BUILD_STATIC_LIBS)
   SET(CosmoTool_local CosmoTool)
 ENDIF(BUILD_SHARED_LIBS AND BUILD_STATIC_LIBS)
 
-find_path(NETCDF_INCLUDE_PATH NAMES netcdf.h)
-find_path(NETCDFCPP_INCLUDE_PATH NAMES netcdfcpp.h netcdf)
-find_path(GSL_INCLUDE_PATH NAMES gsl/gsl_blas.h)
-find_library(NETCDFCPP_LIBRARY NAMES netcdf_c++ netcdf_c++4)
+include(${CMAKE_SOURCE_DIR}/external/external_build.cmake)
 
 IF(EXISTS ${NETCDFCPP_INCLUDE_PATH}/netcdf AND ${NETCDFCPP_LIBRARY} MATCHES "netcdf_c\\+\\+4")
   SET(FOUND_NETCDF4 1)
@@ -39,52 +38,20 @@ ELSE(EXISTS ${NETCDFCPP_INCLUDE_PATH}/netcdf AND ${NETCDFCPP_LIBRARY} MATCHES "n
   FILE(WRITE ${CMAKE_BINARY_DIR}/src/ctool_netcdf_ver.hpp "#undef NETCDFCPP4")
 ENDIF(EXISTS ${NETCDFCPP_INCLUDE_PATH}/netcdf AND ${NETCDFCPP_LIBRARY} MATCHES "netcdf_c\\+\\+4")
 
-find_library(NETCDF_LIBRARY netcdf)
-find_library(GSL_LIBRARY gsl)
-find_library(GSLCBLAS_LIBRARY gslcblas)
-
 find_program(CYTHON cython)
 
-find_package(Boost 1.53)
-
-include(${CMAKE_SOURCE_DIR}/external/external_build.cmake)
-
 set(HDF5_FIND_COMPONENTS HL CXX)
 if(HDF5_ROOTDIR)
   SET(ENV{HDF5_ROOT} ${HDF5_ROOTDIR})
 endif(HDF5_ROOTDIR)
 include(FindHDF5)
 
-include(FindPkgConfig)
 
-pkg_check_modules(FFTW3 fftw3>=3.3)
-pkg_check_modules(FFTW3F fftw3f>=3.3)
-pkg_check_modules(EIGEN3 eigen3)
-
-
-find_library(FFTW3F_LIBRARY_FULL fftw3f PATHS ${FFTW3F_LIBDIR} NO_DEFAULT_PATH)
-find_library(FFTW3_LIBRARY_FULL fftw3 PATHS ${FFTW3_LIBDIR} NO_DEFAULT_PATH)
-
-include(FindPackageHandleStandardArgs)
 set(NETCDF_FIND_REQUIRED TRUE)
 set(GSL_FIND_REQUIRED TRUE)
 FIND_PACKAGE_HANDLE_STANDARD_ARGS(NetCDF DEFAULT_MSG NETCDF_LIBRARY NETCDFCPP_LIBRARY NETCDF_INCLUDE_PATH)
 FIND_PACKAGE_HANDLE_STANDARD_ARGS(GSL DEFAULT_MSG GSL_LIBRARY GSLCBLAS_LIBRARY GSL_INCLUDE_PATH)
 
-IF(ENABLE_OPENMP)
-
-  IF (NOT OPENMP_FOUND)
-    MESSAGE(ERROR "No known compiler option for enabling OpenMP")
-  ENDIF(NOT OPENMP_FOUND)
-
-  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
-  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
-  SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${OpenMP_C_FLAGS}")
-ENDIF(ENABLE_OPENMP)
-
-
-
-set(GSL_LIBRARIES ${GSL_LIBRARY} ${GSLCBLAS_LIBRARY})
 
 # CPACK Configuration
 SET(CPACK_PACKAGE_DESCRIPTION_SUMMARY "A toolbox for impatient cosmologists")
diff --git a/external/external_build.cmake b/external/external_build.cmake
index 93f02a5..edbf6ae 100644
--- a/external/external_build.cmake
+++ b/external/external_build.cmake
@@ -1,3 +1,30 @@
+include(FindOpenMP)
+
+OPTION(ENABLE_OPENMP "Set to Yes if Healpix and/or you need openMP" OFF)
+
+SET(FFTW_URL "http://www.fftw.org/fftw-3.3.3.tar.gz" CACHE URL "URL to download FFTW from")
+SET(EIGEN_URL "http://bitbucket.org/eigen/eigen/get/3.1.4.tar.gz" CACHE URL "URL to download Eigen from")
+SET(GENGETOPT_URL "ftp://ftp.gnu.org/gnu/gengetopt/gengetopt-2.22.5.tar.gz" CACHE STRING "URL to download gengetopt from")
+SET(HDF5_URL "http://www.hdfgroup.org/ftp/HDF5/releases/hdf5-1.8.9/src/hdf5-1.8.9.tar.gz" CACHE STRING "URL to download HDF5 from")
+SET(NETCDF_URL "http://www.unidata.ucar.edu/downloads/netcdf/ftp/netcdf-4.1.3.tar.gz" CACHE STRING "URL to download NetCDF from")
+SET(BOOST_URL "http://sourceforge.net/projects/boost/files/boost/1.49.0/boost_1_49_0.tar.gz/download" CACHE STRING "URL to download Boost from")
+SET(GSL_URL "ftp://ftp.gnu.org/gnu/gsl/gsl-1.15.tar.gz" CACHE STRING "URL to download GSL from ")
+mark_as_advanced(FFTW_URL EIGEN_URL HDF5_URL NETCDF_URL BOOST_URL GSL_URL)
+
+
+IF(ENABLE_OPENMP)
+  IF (NOT OPENMP_FOUND)
+    MESSAGE(ERROR "No known compiler option for enabling OpenMP")
+  ENDIF(NOT OPENMP_FOUND)
+
+  SET(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} ${OpenMP_C_FLAGS}")
+  SET(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${OpenMP_CXX_FLAGS}")
+  SET(CMAKE_EXE_LINKER_FLAGS "${CMAKE_EXE_LINKER_FLAGS} ${OpenMP_C_FLAGS}")
+ENDIF(ENABLE_OPENMP)
+
+
+SET(BUILD_PREFIX ${CMAKE_BINARY_DIR}/external_build)
+SET(EXT_INSTALL ${CMAKE_BINARY_DIR}/ext_install)
 
 if (ENABLE_SHARP)
   SET(SHARP_SOURCE ${CMAKE_SOURCE_DIR}/external/sharp)
@@ -17,6 +44,202 @@ if (ENABLE_SHARP)
 endif (ENABLE_SHARP)
 
 
+###############
+# Build HDF5
+###############
+
+if (INTERNAL_HDF5)
+  SET(HDF5_SOURCE_DIR ${BUILD_PREFIX}/hdf5-prefix/src/hdf5)
+  SET(HDF5_BIN_DIR ${EXT_INSTALL})
+  ExternalProject_Add(hdf5
+    PREFIX ${BUILD_PREFIX}/hdf5-prefix
+    URL ${HDF5_URL}
+    CONFIGURE_COMMAND ${HDF5_SOURCE_DIR}/configure
+           --disable-shared --enable-cxx --with-pic
+	   --prefix=${HDF5_BIN_DIR} --libdir=${HDF5_BIN_DIR}/lib 
+	   CPPFLAGS=${CONFIGURE_CPP_FLAGS} CC=${CMAKE_C_COMPILER} 
+	   CXX=${CMAKE_CXX_COMPILER}
+    BUILD_IN_SOURCE 1
+    INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+  )
+  SET(cosmotool_DEPS ${cosmotool_DEPS} hdf5)
+  SET(hdf5_built hdf5)
+  set(HDF5_LIBRARY ${HDF5_BIN_DIR}/lib/libhdf5.a CACHE STRING "HDF5 lib" FORCE)
+  set(HDF5_CPP_LIBRARY ${HDF5_BIN_DIR}/lib/libhdf5_cpp.a CACHE STRING "HDF5 C++ lib" FORCE)
+  set(HDF5HL_LIBRARY ${HDF5_BIN_DIR}/lib/libhdf5_hl.a CACHE STRING "HDF5-HL lib" FORCE)
+  set(HDF5HL_CPP_LIBRARY ${HDF5_BIN_DIR}/lib/libhdf5_hl_cpp.a CACHE STRING "HDF5-HL C++ lib" FORCE)
+  SET(HDF5_INCLUDE_PATH ${HDF5_BIN_DIR}/include CACHE STRING "HDF5 include path" FORCE)
+  SET(ENV{HDF5_ROOT} ${HDF5_BIN_DIR})
+  SET(HDF5_ROOTDIR ${HDF5_BIN_DIR})
+  SET(CONFIGURE_LDFLAGS "${CONFIGURE_LDFLAGS} -L${HDF5_BIN_DIR}/lib")
+else(INTERNAL_HDF5)
+  find_path(HDF5_INCLUDE_PATH hdf5.h)
+  find_library(HDF5_LIBRARY hdf5)
+  find_library(HDF5_CPP_LIBRARY hdf5_cpp)
+  find_library(HDF5HL_CPP_LIBRARY hdf5_hl_cpp)
+  find_library(HDF5HL_LIBRARY hdf5_hl)
+endif (INTERNAL_HDF5)
+SET(CONFIGURE_CPP_FLAGS "${CONFIGURE_CPP_FLAGS} -I${HDF5_INCLUDE_PATH}")
+mark_as_advanced(HDF5_INCLUDE_PATH HDF5_LIBRARY HDF5_CPP_LIBRARY HDF5HL_LIBRARY HDF5HL_CPP_LIBRARY)
+
+###############
+# Build NetCDF
+###############
+
+
+if (INTERNAL_NETCDF)
+  SET(NETCDF_SOURCE_DIR ${BUILD_PREFIX}/netcdf-prefix/src/netcdf)
+  SET(NETCDF_BIN_DIR ${EXT_INSTALL})
+  SET(CONFIGURE_CPP_FLAGS "${CONFIGURE_CPP_FLAGS} -I${NETCDF_BIN_DIR}/include")
+  SET(CONFIGURE_LDFLAGS "${CONFIGURE_LDFLAGS} -L${NETCDF_BIN_DIR}/lib")
+  SET(EXTRA_NC_FLAGS CPPFLAGS=${CONFIGURE_CPP_FLAGS} LDFLAGS=${CONFIGURE_LDFLAGS})
+  ExternalProject_Add(netcdf
+    DEPENDS ${hdf5_built}
+    PREFIX ${BUILD_PREFIX}/netcdf-prefix
+    URL ${NETCDF_URL}
+    CONFIGURE_COMMAND ${NETCDF_SOURCE_DIR}/configure
+         --prefix=${NETCDF_BIN_DIR} --libdir=${NETCDF_BIN_DIR}/lib
+         --enable-netcdf-4  --with-pic --disable-shared --disable-dap 
+         --disable-cdmremote --disable-rpc 
+         --disable-examples ${EXTRA_NC_FLAGS} CC=${CMAKE_C_COMPILER}
+         CXX=${CMAKE_CXX_COMPILER}
+    BUILD_IN_SOURCE 1
+    INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+  )
+  SET(CONFIGURE_CPP_LDFLAGS "${CONFIGURE_LDFLAGS}")
+  SET(EXTRA_NC_FLAGS CPPFLAGS=${CONFIGURE_CPP_FLAGS} LDFLAGS=${CONFIGURE_CPP_LDFLAGS})
+  SET(cosmotool_DEPS ${cosmotool_DEPS} netcdf)
+  SET(NETCDF_LIBRARY ${NETCDF_BIN_DIR}/lib/libnetcdf.a CACHE STRING "NetCDF lib" FORCE)
+  SET(NETCDFCPP_LIBRARY ${NETCDF_BIN_DIR}/lib/libnetcdf_c++.a CACHE STRING "NetCDF-C++ lib" FORCE)
+  SET(NETCDF_INCLUDE_PATH ${NETCDF_BIN_DIR}/include CACHE STRING "NetCDF include" FORCE)
+  SET(NETCDFCPP_INCLUDE_PATH ${NETCDF_INCLUDE_PATH} CACHE STRING "NetCDF C++ include path" FORCE)
+
+ELSE(INTERNAL_NETCDF)
+  find_path(NETCDF_INCLUDE_PATH NAMES netcdf.h)
+  find_path(NETCDFCPP_INCLUDE_PATH NAMES netcdfcpp.h netcdf)
+  find_library(NETCDF_LIBRARY netcdf)
+  find_library(NETCDFCPP_LIBRARY NAMES netcdf_c++ netcdf_c++4)
+
+  SET(CONFIGURE_CPP_FLAGS ${CONFIGURE_CPP_FLAGS} 
+          -I${NETCDF_INCLUDE_PATH} -I${NETCDFCPP_INCLUDE_PATH})          
+endif (INTERNAL_NETCDF)
+mark_as_advanced(NETCDF_LIBRARY NETCDFCPP_LIBRARY NETCDF_INCLUDE_PATH NETCDFCPP_INCLUDE_PATH)
+
+##################
+# Build BOOST
+##################
+
+if (INTERNAL_BOOST)
+  SET(BOOST_SOURCE_DIR ${BUILD_PREFIX}/boost-prefix/src/boost)
+  ExternalProject_Add(boost
+    URL ${BOOST_URL}
+    PREFIX ${BUILD_PREFIX}/boost-prefix
+    CONFIGURE_COMMAND 
+           ${BOOST_SOURCE_DIR}/bootstrap.sh --prefix=${CMAKE_BINARY_DIR}/ext_build/boost
+    BUILD_IN_SOURCE 1
+    BUILD_COMMAND ${BOOST_SOURCE_DIR}/b2 --with-exception 
+    INSTALL_COMMAND echo "No install"
+  )
+  set(Boost_INCLUDE_DIRS ${BOOST_SOURCE_DIR} CACHE STRING "Boost path" FORCE)
+  set(Boost_LIBRARIES ${BOOST_SOURCE_DIR}/stage/lib/libboost_python.a CACHE STRING "Boost libraries" FORCE)
+
+ELSE (INTERNAL_BOOST)
+  find_package(Boost 1.53)
+endif (INTERNAL_BOOST)
+mark_as_advanced(Boost_INCLUDE_DIRS Boost_LIBRARIES)
+
+##################
+# Build GSL
+##################
+
+IF(INTERNAL_GSL)
+  SET(GSL_SOURCE_DIR ${BUILD_PREFIX}/gsl-prefix/src/gsl)
+  ExternalProject_Add(gsl
+    URL ${GSL_URL}
+    PREFIX ${BUILD_PREFIX}/gsl-prefix
+    CONFIGURE_COMMAND ${GSL_SOURCE_DIR}/configure
+           --prefix=${EXT_INSTALL} --disable-shared
+           --with-pic
+           CPPFLAGS=${CONFIGURE_CPP_FLAGS} CC=${CMAKE_C_COMPILER} CXX=${CMAKE_CXX_COMPILER}
+    BUILD_IN_SOURCE 1
+    BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
+    INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+  )
+  SET(GSL_INTERNAL_LIBS ${EXT_INSTALL}/lib)
+  SET(GSL_LIBRARY ${GSL_INTERNAL_LIBS}/libgsl.a CACHE STRING "GSL internal path" FORCE)
+  SET(GSLCBLAS_LIBRARY ${GSL_INTERNAL_LIBS}/libgslcblas.a CACHE STRING "GSL internal path" FORCE)
+  set(GSL_INCLUDE_PATH ${CMAKE_BINARY_DIR}/ext_build/gsl/include CACHE STRING "GSL internal path" FORCE)
+  SET(cosmotool_DEPS ${cosmotool_DEPS} gsl)
+ELSE(INTERNAL_GSL)
+  find_path(GSL_INCLUDE_PATH NAMES gsl/gsl_blas.h)
+  find_library(GSL_LIBRARY gsl)
+  find_library(GSLCBLAS_LIBRARY gslcblas)
+
+  set(GSL_LIBRARIES ${GSL_LIBRARY} ${GSLCBLAS_LIBRARY})
+
+ENDIF(INTERNAL_GSL)
+mark_as_advanced(GSL_LIBRARY GSLCBLAS_LIBRARY GSL_INCLUDE_PATH)
+
+
+#############
+# Build FFTW
+#############
+
+IF(INTERNAL_FFTW)
+	SET(EXTRA_FFTW_CONF)
+	IF(HAVE_SSE)
+		SET(EXTRA_FFTW_CONF ${EXTRA_FFTW_CONF} --enable-sse)
+	ENDIF(HAVE_SSE)
+	IF(HAVE_SSE2)
+		SET(EXTRA_FFTW_CONF ${EXTRA_FFTW_CONF} --enable-sse2)
+	ENDIF(HAVE_SSE2)
+	IF(HAVE_AVX)
+		SET(EXTRA_FFTW_CONF ${EXTRA_FFTW_CONF} --enable-avx)
+	ENDIF(HAVE_AVX)
+
+  SET(cosmotool_DEPS ${cosmotool_DEPS} fftw)
+  SET(FFTW_SOURCE ${BUILD_PREFIX}/fftw-prefix/src/fftw)
+  ExternalProject_Add(fftw
+     URL ${FFTW_URL}
+     PREFIX ${BUILD_PREFIX}/fftw-prefix
+     CONFIGURE_COMMAND 
+           ${FFTW_SOURCE}/configure
+                 --prefix=${EXT_INSTALL}
+		 ${EXTRA_FFTW_CONF} --disable-shared --enable-threads
+     BUILD_COMMAND ${CMAKE_MAKE_PROGRAM}
+     INSTALL_COMMAND ${CMAKE_MAKE_PROGRAM} install
+  )
+  SET(FFTW3_LIBRARY_DIRS ${EXT_INSTALL}/lib)
+  SET(FFTW3_INCLUDE_PATH ${EXT_INSTALL}/include)
+  SET(FFTW3_THREADS ${EXT_INSTALL}/lib/libfftw3_threads.a)
+  SET(FFTW3_LIBRARIES ${EXT_INSTALL}/lib/libfftw3.a)
+  
+ELSE (INTERNAL_FFTW)  
+  pkg_check_modules(FFTW3 fftw3>=3.3)
+  pkg_check_modules(FFTW3F fftw3f>=3.3)
+
+  find_library(FFTW3F_LIBRARY_FULL fftw3f PATHS ${FFTW3F_LIBDIR} NO_DEFAULT_PATH)
+  find_library(FFTW3_LIBRARY_FULL fftw3 PATHS ${FFTW3_LIBDIR} NO_DEFAULT_PATH)
+
+ENDIF(INTERNAL_FFTW)                   
+
+
+##############
+# Build Eigen
+##############
+IF (INTERNAL_EIGEN)
+  ExternalProject_Add(eigen
+     URL ${EIGEN_URL}
+     PREFIX ${BUILD_PREFIX}/eigen-prefix
+     CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${EXT_INSTALL}
+  )
+  SET(EIGEN_INCLUDE_PATH ${EXT_INSTALL}/include/eigen3)
+
+ELSE (INTERNAL_EIGEN)
+  pkg_check_modules(EIGEN3 eigen3)
+ENDIF(INTERNAL_EIGEN)
+
+
 
 SET(OMPTL_BUILD_DIR ${CMAKE_BINARY_DIR}/omptl-prefix/src/omptl)
 ExternalProject_Add(omptl
diff --git a/python_sample/icgen/borgicgen.py b/python_sample/icgen/borgicgen.py
index fcfee2c..53c4c60 100644
--- a/python_sample/icgen/borgicgen.py
+++ b/python_sample/icgen/borgicgen.py
@@ -4,10 +4,10 @@ import cosmolopy as cpy
 from cosmogrowth import *
 import borgadaptor as ba
 
-def gen_posgrid(N, L):
+def gen_posgrid(N, L, delta=1, dtype=np.float32):
     """ Generate an ordered lagrangian grid"""
 
-    ix = (np.arange(N)*L/N).astype(np.float32)
+    ix = (np.arange(N)*L/N*delta).astype(dtype)
 
     x = ix[:,None,None].repeat(N, axis=1).repeat(N, axis=2)
     y = ix[None,:,None].repeat(N, axis=0).repeat(N, axis=2)