diff --git a/.github/workflows/run_all_quickbuilds.yml b/.github/workflows/run_all_quickbuilds.yml
index a153aa0064..49f7468b7c 100644
--- a/.github/workflows/run_all_quickbuilds.yml
+++ b/.github/workflows/run_all_quickbuilds.yml
@@ -68,6 +68,9 @@ jobs:
             *GMI* | *GOES* | *forward_operators* | *NSIDC* )
               cp /home/mkmf.template.rttov.gfortran  mkmf.template
               ;;
+            *library*)
+              cp ../developer_tests/library/mkmf.template.gfortran mkmf.template
+              ;;
             *)
               cp mkmf.template.gfortran mkmf.template
               echo 'FFLAGS = -g -Wuninitialized -Wunused -ffree-line-length-none -fbounds-check -fbacktrace -ffpe-trap=invalid,zero,overflow $(INCS)' >> mkmf.template
diff --git a/.gitignore b/.gitignore
index 5d1f27c778..7d4937541c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,5 @@
+*.a
+*.so
 *.mod
 *.o
 *.swp
diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index d50c46d295..5e2c1706f5 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -22,6 +22,12 @@ individual files.
 
 The changes are now listed with the most recent at the top.
 
+**July 26 2024 :: Library build tools for DART. Tag v11.6.0**
+
+- Buildtools for compiling DART as a shared or a static library.
+- Bugfix: correct order of arguments in count_state_ens_copies for 'input'
+  stages_to_write.
+
 **July 11 2024 :: Bgrid documentation and scripting fix. Tag v11.5.1**
 
 - Updated Bgrid documentation and removed outdated scripts and files
diff --git a/build_templates/buildfunctions.sh b/build_templates/buildfunctions.sh
index e83475c7e5..f8188a8cad 100644
--- a/build_templates/buildfunctions.sh
+++ b/build_templates/buildfunctions.sh
@@ -84,6 +84,8 @@ for p in ${all_programs[@]}; do
 done
 
 \rm -f -- preprocess
+\rm -f -- libdart.a
+\rm -f -- libdart.so
 cleanpreprocess
 
 }
@@ -253,6 +255,16 @@ fi
      $program
 }
 
+#-------------------------
+# Build a library
+#
+#-------------------------
+function buildlib() {
+findsrc
+$DART/build_templates/mkmf -x -a $DART $m -p $1 \
+     $dartsrc \
+     $EXTRA
+}
 #-------------------------
 # Build a model specific program
 # looks in $DART/models/$MODEL/src/programs for {main}.f90 
diff --git a/build_templates/mkmf b/build_templates/mkmf
index 821982978d..dbd8ea45f1 100755
--- a/build_templates/mkmf
+++ b/build_templates/mkmf
@@ -73,7 +73,7 @@ my $endline = $/;
 my @src_suffixes = ( q/\.F/, q/\.F90/, q/\.c/, q/\.f/, q/\.f90/ );
 my @inc_suffixes = ( q/\.H/, q/\.fh/, q/\.h/, q/\.inc/ );
 push @inc_suffixes, @src_suffixes; # sourcefiles can be includefiles too
-my @tgt_suffixes = ( q/\.a/ );
+my @tgt_suffixes = ( q/\.a/, q/\.so/ );
 
 print "Using MPI wrappers\n" if $opt_w;
 my %compile_cmd;
@@ -481,6 +481,12 @@ print MAKEFILE "tags: \$(SRC)\n\tctags \$(SRC)\n";
 ( $name, $path, $suffix ) = fileparse( $opt_p, @tgt_suffixes );
 if( $suffix eq '.a' ) {
    print MAKEFILE "$opt_p: \$(OBJ)\n\t\$(AR) \$(ARFLAGS) $opt_p \$(OBJ)\n";
+} elsif ( $suffix eq '.so' ) {
+    if ( $opt_w ) {
+       print MAKEFILE "$opt_p: \$(OBJ)\n\t\$(MPILD) \$(SHR) \$(OBJ) -o $opt_p  \$(LDFLAGS)";
+    } else {
+       print MAKEFILE "$opt_p: \$(OBJ)\n\t\$(LD) \$(SHR) \$(OBJ) -o $opt_p  \$(LDFLAGS)";
+   }      
 } elsif ( $opt_w ){
    print MAKEFILE "$opt_p: \$(OBJ)\n\t\$(MPILD) \$(OBJ) -o $opt_p $opt_l \$(LDFLAGS)\n";
 } else {
diff --git a/conf.py b/conf.py
index db0041097f..deb053a0be 100644
--- a/conf.py
+++ b/conf.py
@@ -21,7 +21,7 @@
 author = 'Data Assimilation Research Section'
 
 # The full version, including alpha/beta/rc tags
-release = '11.5.1'
+release = '11.6.0'
 root_doc = 'index'
 
 # -- General configuration ---------------------------------------------------
diff --git a/developer_tests/library/mkmf.template.gfortran b/developer_tests/library/mkmf.template.gfortran
new file mode 100644
index 0000000000..46f8e087f3
--- /dev/null
+++ b/developer_tests/library/mkmf.template.gfortran
@@ -0,0 +1,23 @@
+# Template for GNU gfortran on Linux or Mac OSX
+#
+# DART software - Copyright UCAR. This open source software is provided
+# by UCAR, "as is", without charge, subject to all terms of use at
+# http://www.image.ucar.edu/DAReS/DART/DART_download
+#
+
+MPIFC = mpif90
+MPILD = mpif90
+FC = gfortran
+LD = gfortran
+
+#NETCDF = /opt/local
+
+INCS = -I$(NETCDF)/include
+LIBS = -L$(NETCDF)/lib -lnetcdff -lnetcdf
+FFLAGS  = -O2 -ffree-line-length-none -fPIC $(INCS)
+LDFLAGS = $(FFLAGS) $(LIBS)
+SHR = -shared
+
+# FFLAGS = -g -Wuninitialized -Wunused -ffree-line-length-none -fbounds-check \
+#          -fbacktrace -ffpe-trap=invalid,zero,overflow $(INCS)
+
diff --git a/developer_tests/library/shared/work/input.nml b/developer_tests/library/shared/work/input.nml
new file mode 100644
index 0000000000..a088a84317
--- /dev/null
+++ b/developer_tests/library/shared/work/input.nml
@@ -0,0 +1,18 @@
+&preprocess_nml
+   overwrite_output        = .true.
+   input_obs_def_mod_file  = '../../../../observations/forward_operators/DEFAULT_obs_def_mod.F90'
+   output_obs_def_mod_file = '../../../../observations/forward_operators/obs_def_mod.f90'
+   input_obs_qty_mod_file  = '../../../../assimilation_code/modules/observations/DEFAULT_obs_kind_mod.F90'
+   output_obs_qty_mod_file = '../../../../assimilation_code/modules/observations/obs_kind_mod.f90'
+   obs_type_files          = '../../../../observations/forward_operators/obs_def_1d_state_mod.f90'
+   quantity_files          = '../../../../assimilation_code/modules/observations/oned_quantities_mod.f90'
+   /   
+
+&utilities_nml
+   termlevel      = 1,
+   module_details = .false.,
+   logfilename    = 'dart_log.out',
+   nmlfilename    = 'dart_log.nml',
+   write_nml      = 'file',
+   print_debug    = .false.,
+   /
diff --git a/developer_tests/library/shared/work/quickbuild.sh b/developer_tests/library/shared/work/quickbuild.sh
new file mode 100755
index 0000000000..f9b029fc33
--- /dev/null
+++ b/developer_tests/library/shared/work/quickbuild.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+# DART software - Copyright UCAR. This open source software is provided
+# by UCAR, "as is", without charge, subject to all terms of use at
+# http://www.image.ucar.edu/DAReS/DART/DART_download
+
+main() {
+
+
+export DART=$(git rev-parse --show-toplevel)
+source "$DART"/build_templates/buildfunctions.sh
+
+MODEL=lorenz_96
+LOCATION=oned
+
+# quickbuild arguments
+arguments "$@"
+
+# clean the directory
+\rm -f -- libdart.so *.o *.mod Makefile .cppdefs
+
+# build any NetCDF files from .cdl files
+cdl_to_netcdf
+
+# build and run preprocess before making any other DART executables
+buildpreprocess
+
+# build static library
+buildlib  libdart.so
+
+# clean up
+\rm -f -- *.o 
+
+}
+
+main "$@"
diff --git a/developer_tests/library/static/work/input.nml b/developer_tests/library/static/work/input.nml
new file mode 100644
index 0000000000..a088a84317
--- /dev/null
+++ b/developer_tests/library/static/work/input.nml
@@ -0,0 +1,18 @@
+&preprocess_nml
+   overwrite_output        = .true.
+   input_obs_def_mod_file  = '../../../../observations/forward_operators/DEFAULT_obs_def_mod.F90'
+   output_obs_def_mod_file = '../../../../observations/forward_operators/obs_def_mod.f90'
+   input_obs_qty_mod_file  = '../../../../assimilation_code/modules/observations/DEFAULT_obs_kind_mod.F90'
+   output_obs_qty_mod_file = '../../../../assimilation_code/modules/observations/obs_kind_mod.f90'
+   obs_type_files          = '../../../../observations/forward_operators/obs_def_1d_state_mod.f90'
+   quantity_files          = '../../../../assimilation_code/modules/observations/oned_quantities_mod.f90'
+   /   
+
+&utilities_nml
+   termlevel      = 1,
+   module_details = .false.,
+   logfilename    = 'dart_log.out',
+   nmlfilename    = 'dart_log.nml',
+   write_nml      = 'file',
+   print_debug    = .false.,
+   /
diff --git a/developer_tests/library/static/work/quickbuild.sh b/developer_tests/library/static/work/quickbuild.sh
new file mode 100755
index 0000000000..25b868ac39
--- /dev/null
+++ b/developer_tests/library/static/work/quickbuild.sh
@@ -0,0 +1,36 @@
+#!/usr/bin/env bash
+
+# DART software - Copyright UCAR. This open source software is provided
+# by UCAR, "as is", without charge, subject to all terms of use at
+# http://www.image.ucar.edu/DAReS/DART/DART_download
+
+main() {
+
+
+export DART=$(git rev-parse --show-toplevel)
+source "$DART"/build_templates/buildfunctions.sh
+
+MODEL=lorenz_96
+LOCATION=oned
+
+# quickbuild arguments
+arguments "$@"
+
+# clean the directory
+\rm -f -- libdart.a *.o *.mod Makefile .cppdefs
+
+# build any NetCDF files from .cdl files
+cdl_to_netcdf
+
+# build and run preprocess before making any other DART executables
+buildpreprocess
+
+# build static library
+buildlib  libdart.a
+
+# clean up
+\rm -f -- *.o 
+
+}
+
+main "$@"
diff --git a/developer_tests/library/test_libraries.sh b/developer_tests/library/test_libraries.sh
new file mode 100755
index 0000000000..614e89737b
--- /dev/null
+++ b/developer_tests/library/test_libraries.sh
@@ -0,0 +1,97 @@
+#!/usr/bin/env bash
+
+set -e
+export DART=$(git rev-parse --show-toplevel)
+
+main () {
+
+NETCDF_LIB=/opt/local/
+testdir=$(pwd)
+
+# remove any previous test directoires
+rm -rf nolib
+rm -rf sharedlib
+rm -rf staticlib
+
+# use library mkmf.template
+cp "$testdir"/mkmf.template.gfortran "$DART"/build_templates/mkmf.template
+
+# regular filter build - this goes first so test directories get *.nc and obs_seq.out input files
+cd "$DART"/models/lorenz_96/work
+./quickbuild.sh clean
+./quickbuild.sh mpif08 filter
+rm *.o *.mod
+
+#-----------------
+# setup test direcories
+cd "$testdir"
+cp -r "$DART"/models/lorenz_96/work nolib
+cp -r "$DART"/models/lorenz_96/work sharedlib
+cp -r "$DART"/models/lorenz_96/work staticlib
+
+#-----------------
+# shared library build
+cd "$DART"/developer_tests/library/shared/work
+./quickbuild.sh clean
+./quickbuild.sh mpif08
+
+mpif90 -o filter "$DART"/assimilation_code/programs/filter/filter.f90 -I.  -L. -ldart
+
+#-----------------
+# static library build
+cd "$DART"/developer_tests/library/static/work
+./quickbuild.sh clean
+./quickbuild.sh mpif08
+
+mpif90 "$DART"/assimilation_code/programs/filter/filter.f90  -I. -L. -ldart  -L/$NETCDF_LIB -lnetcdff -o filter
+
+#-----------------
+# copy executables built from libraries to test directories
+cd "$testdir"/sharedlib
+rm filter
+cp "$DART"/developer_tests/library/shared/work/filter .
+cp "$DART"/developer_tests/library/shared/work/libdart.so .
+
+cd "$testdir"/staticlib
+rm filter
+cp "$DART"/developer_tests/library/static/work/filter .
+
+#-----------------
+# run filter
+cd "$testdir"/nolib/
+mpirun -n 4 ./filter
+
+cd "$testdir"/sharedlib/
+export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:$(pwd) 
+mpirun -n 4 ./filter
+
+cd "$testdir"/staticlib/
+mpirun -n 4 ./filter
+
+check_bitwise "$testdir"/nolib/ "$testdir"/sharedlib/
+check_bitwise "$testdir"/nolib/ "$testdir"/staticlib/
+
+}
+
+#-----------------
+check_bitwise () {
+diff -s "$1"/obs_seq.final "$2"/obs_seq.final
+
+netcdffiles=(\
+analysis.nc
+filter_input.nc
+filter_output.nc
+perfect_input.nc
+preassim.nc \
+)
+
+for f in "${netcdffiles[@]}"
+do
+  echo -n "$f" " "  
+  nccmp -d "$1"/"$f" "$2"/"$f"
+  echo "" 
+done
+}
+
+main "$@"
+
diff --git a/guide/quickbuild.rst b/guide/quickbuild.rst
index 04cc8678e9..7d09ec624f 100644
--- a/guide/quickbuild.rst
+++ b/guide/quickbuild.rst
@@ -242,3 +242,20 @@ finds your new code and ignores any code you do not want compiled.
    a directory, a list of files, or a single file.
 
 
+Building DART as a library
+--------------------------
+
+For developers who want to build DART as a library for use with another applications, we provide
+the buildlib buildfunction.   
+
+.. code-block :: bash
+
+   buildlib libdart.a  # for a static library
+   buildlib libdart.so # for a shared library
+
+
+Example quickbuild.sh scripts for building a shared and a static library are given in 
+``DART/developer_tests/library/{shared|static}/work``.
+
+
+