diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3a644ef583..f6db881f48 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -540,6 +540,12 @@ set(NCIO_MINBLOCKSIZE 256 CACHE STRING "Minimum I/O Blocksize for netCDF classic
 if(NETCDF_ENABLE_NETCDF4)
   set(USE_NETCDF4 ON CACHE BOOL "")
   set(NETCDF_ENABLE_NETCDF4 ON CACHE BOOL "")
+
+  # Configure the nc4dispatch.c file to H5Linclude plugin path at
+  # library initialization.
+  configure_file("${CMAKE_SOURCE_DIR}/libsrc4/nc4dispatch.c.in"
+    "${CMAKE_BINARY_DIR}/libsrc4/nc4dispatch.c" @ONLY NEWLINE_STYLE LF)
+  
 else()
   set(USE_HDF4_FILE_TESTS OFF)
   set(USE_HDF4 OFF)
diff --git a/Makefile.am b/Makefile.am
index 8ccfd6a4d2..560817496d 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -25,7 +25,7 @@ TEST_EXTENSIONS = .sh
 # comment thread at https://github.com/Unidata/netcdf-c/pull/2348
 # for more information.
 ##
-AM_DISTCHECK_CONFIGURE_FLAGS = --without-plugin-dir
+#AM_DISTCHECK_CONFIGURE_FLAGS = --without-plugin-dir
 
 # These files get added to the distribution.
 EXTRA_DIST = README.md COPYRIGHT INSTALL.md test_prog.c lib_flags.am	\
diff --git a/configure.ac b/configure.ac
index 9888d0af65..ea735169c7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1618,7 +1618,7 @@ if test "x$enable_hdf5" = xyes; then
    # H5Pset_fapl_mpiposix and H5Pget_fapl_mpiposix have been removed since HDF5 1.8.12.
    # Use H5Pset_fapl_mpio and H5Pget_fapl_mpio, instead.
 
-   AC_CHECK_FUNCS([H5Pget_fapl_mpio H5Pset_deflate H5Z_SZIP H5Pset_all_coll_metadata_ops H5Literate H5Literate2])
+   AC_CHECK_FUNCS([H5Pget_fapl_mpio H5Pset_deflate H5Z_SZIP H5Pset_all_coll_metadata_ops H5Literate H5Literate2 H5PLappend])
 
    # Check to see if HDF5 library has collective metadata APIs, (HDF5 >= 1.10.0)
    if test "x$ac_cv_func_H5Pset_all_coll_metadata_ops" = xyes; then
@@ -2094,9 +2094,14 @@ AC_SUBST(STD_FILTERS,[$std_filters])
 
 # If user wants, then install selected standard filters
 AC_MSG_CHECKING([whether and where we should install plugins])
-AC_ARG_WITH([plugin-dir], [AS_HELP_STRING([--with-plugin-dir=<absolute directory>|no|--without-plugin-dir],
+AC_ARG_WITH([plugin-dir], [AS_HELP_STRING([--with-plugin-dir=<absolute directory>|yes|no|--without-plugin-dir],
               [Install selected standard filters in specified or default directory])],
 	      [],[with_plugin_dir=no])
+if test "x$have_zstd" = xyes; then
+   if test "x$with_plugin_dir" = xno; then
+      with_plugin_dir=yes
+   fi
+fi
 AC_MSG_RESULT([$with_plugin_dir])
 if test "x$with_plugin_dir" = xno ; then # option missing|disabled
     with_plugin_dir=no
@@ -2237,6 +2242,7 @@ AC_CONFIG_FILES(dap4_test/findtestserver4.c:ncdap_test/findtestserver.c.in)
 AC_CONFIG_FILES(dap4_test/pingurl4.c:ncdap_test/pingurl.c)
 AC_CONFIG_FILES([h5_test/run_par_tests.sh], [chmod ugo+x h5_test/run_par_tests.sh])
 AC_CONFIG_FILES([nc_test4/run_par_test.sh], [chmod ugo+x nc_test4/run_par_test.sh])
+AC_CONFIG_FILES([libsrc4/nc4dispatch.c], [chmod ugo+x nc_test4/run_par_test.sh])
 AC_CONFIG_FILES([nc_perf/run_par_bm_test.sh], [chmod ugo+x nc_perf/run_par_bm_test.sh])
 AC_CONFIG_FILES([nc_perf/run_gfs_test.sh], [chmod ugo+x nc_perf/run_gfs_test.sh])
 AC_CONFIG_FILES(nczarr_test/timer_utils.h:unit_test/timer_utils.h)
diff --git a/libsrc4/CMakeLists.txt b/libsrc4/CMakeLists.txt
index 09227318e6..75313f1122 100644
--- a/libsrc4/CMakeLists.txt
+++ b/libsrc4/CMakeLists.txt
@@ -6,7 +6,7 @@
 # See netcdf-c/COPYRIGHT file for more info.
 # Process these files with m4.
 
-set(libsrc4_SOURCES nc4dispatch.c nc4attr.c nc4dim.c nc4grp.c
+set(libsrc4_SOURCES ${netCDF_BINARY_DIR}/libsrc4/nc4dispatch.c nc4attr.c nc4dim.c nc4grp.c
 nc4internal.c nc4type.c nc4var.c ncfunc.c ncindex.c nc4cache.c)
 
 add_library(netcdf4 OBJECT ${libsrc4_SOURCES})
diff --git a/libsrc4/nc4dispatch.c b/libsrc4/nc4dispatch.c.in
similarity index 88%
rename from libsrc4/nc4dispatch.c
rename to libsrc4/nc4dispatch.c.in
index 2aa5987824..58aa436f16 100644
--- a/libsrc4/nc4dispatch.c
+++ b/libsrc4/nc4dispatch.c.in
@@ -15,6 +15,9 @@
 #include "nc4internal.h"
 #include "nc4dispatch.h"
 #include "nc.h"
+#ifdef HAVE_H5PLAPPEND
+#include "hdf5.h"
+#endif
 
 /* If user-defined formats are in use, we need to declare their
  * dispatch tables. */
@@ -52,6 +55,13 @@ NC4_initialize(void)
         return ret;
 #endif /* USE_UDF0 */
 
+#ifdef HAVE_H5PLAPPEND
+    /* Add the place where plugins were installed to the plugin
+     * path. */
+    if ((ret = H5PLappend("@PLUGIN_INSTALL_DIR@")))
+        return ret;
+#endif
+
 #ifdef LOGGING
     if(getenv(NCLOGLEVELENV) != NULL) {
         char* slevel = getenv(NCLOGLEVELENV);
diff --git a/nc_test4/CMakeLists.txt b/nc_test4/CMakeLists.txt
index 33a105f5b2..bd56f3e6cd 100644
--- a/nc_test4/CMakeLists.txt
+++ b/nc_test4/CMakeLists.txt
@@ -102,6 +102,11 @@ IF(HAVE_H5Z_SZIP)
   ENDIF()
 ENDIF()
 
+IF(HAVE_ZSTD)
+  BUILD_BIN_TEST(tst_zstd)
+  add_sh_test(nc_test4 run_zstd_test)
+ENDIF()
+
 
 # Copy some test files from current source dir to out-of-tree build dir.
 FILE(GLOB COPY_FILES ${CMAKE_CURRENT_SOURCE_DIR}/*.nc ${CMAKE_CURRENT_SOURCE_DIR}/ref_bzip2.c ${CMAKE_CURRENT_SOURCE_DIR}/*.sh ${CMAKE_CURRENT_SOURCE_DIR}/*.h5 ${CMAKE_CURRENT_SOURCE_DIR}/*.cdl)
diff --git a/nc_test4/Makefile.am b/nc_test4/Makefile.am
index 6d1c0e2e44..4776403801 100644
--- a/nc_test4/Makefile.am
+++ b/nc_test4/Makefile.am
@@ -11,10 +11,10 @@
 include $(top_srcdir)/lib_flags.am
 
 # Un comment to use a more verbose test driver
-#SH_LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
-#sh_LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
-#LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
-#TESTS_ENVIRONMENT = export SETX=1;
+SH_LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
+sh_LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
+LOG_DRIVER = $(SHELL) $(top_srcdir)/test-driver-verbose
+TESTS_ENVIRONMENT = export SETX=1;
 
 TEST_EXTENSIONS = .sh
 
@@ -113,6 +113,12 @@ endif # NETCDF_ENABLE_PLUGINS
 endif # USE_HDF5
 endif # NETCDF_BUILD_UTILITIES
 
+# Zstandard tests.
+if HAVE_ZSTD
+check_PROGRAMS += tst_zstd
+TESTS += run_zstd_test.sh
+endif # HAVE_ZSTD
+
 # This are extra tests that will only be run if netcdf-4 is configured
 # with --enable-parallel-tests.
 if TEST_PARALLEL4
diff --git a/nc_test4/run_zstd_test.sh b/nc_test4/run_zstd_test.sh
new file mode 100755
index 0000000000..cd234c43a9
--- /dev/null
+++ b/nc_test4/run_zstd_test.sh
@@ -0,0 +1,32 @@
+#!/bin/sh
+
+# This .in file is processed at build time into a shell that runs some
+# zstd for netCDF.
+
+# Ed Hartnett, 8/10/24
+
+set -e
+
+if test "x$srcdir" = x ; then srcdir=`pwd`; fi
+. ../test_common.sh
+
+# Load the findplugins function
+. ${builddir}/findplugin.sh
+echo "findplugin.sh loaded"
+echo "${HDF5_PLUGIN_DIR}"
+
+findplugin h5zstd
+echo "HDF5_PLUGIN_DIR=$HDF5_PLUGIN_DIR"
+./tst_zstd
+
+
+echo
+echo "Testing Zstandard compression..."
+
+export HDF5_PLUGIN_PATH="${HDF5_PLUGIN_DIR}"
+echo "set HDF5_PLUGIN_PATH: ${HDF5_PLUGIN_PATH}"
+
+echo "SUCCESS!"
+
+
+
diff --git a/nc_test4/tst_zstd.c b/nc_test4/tst_zstd.c
new file mode 100644
index 0000000000..7ae201fbf6
--- /dev/null
+++ b/nc_test4/tst_zstd.c
@@ -0,0 +1,78 @@
+/* This is part of the netCDF package.
+   Copyright 2018 University Corporation for Atmospheric Research/Unidata
+   See COPYRIGHT file for conditions of use.
+
+   Test netcdf-4 variables.
+   Ed Hartnett, 8/7/24
+*/
+
+#include "nc_tests.h"
+#include "err_macros.h"
+#include "netcdf.h"
+
+#define FILE_NAME "tst_zstd.nc"
+#define VAR_FLOAT_NAME "GALE_data"
+#define VAR_DOUBLE_NAME "ERICA_data"
+#define NDIM2 2
+#define DIM1_NAME "x"
+#define DIM1_LEN 2
+#define DIM2_NAME "y"
+#define DIM2_LEN 3
+
+int
+main(int argc, char **argv)
+{
+   int ncid, dimids[NDIM2];
+   int float_varid, double_varid;
+   float float_in[DIM1_LEN][DIM2_LEN], float_out[DIM1_LEN][DIM2_LEN] = {{-.1f, 9999.99f, 100.001f},{-.1f, 9999.99f, 100.001f}};
+   double double_in[DIM1_LEN][DIM2_LEN], double_out[DIM1_LEN][DIM2_LEN] = {{0.02, .1128, 1090.1},{0.02, .1128, 1090.1}};
+   int i, j, ret;
+
+
+   printf("\n*** Testing netcdf-4 zstd compression.\n");
+
+   printf("*** testing netcdf-4 zstd with float...");
+   {
+      int nvars_in, varids_in[2];
+
+      /* Create a netcdf file with one dim and two vars. */
+      if (nc_create(FILE_NAME, NC_NETCDF4, &ncid)) ERR;
+      if (nc_def_dim(ncid, DIM1_NAME, DIM1_LEN, &dimids[0])) ERR;
+      if (nc_def_dim(ncid, DIM2_NAME, DIM2_LEN, &dimids[1])) ERR;
+      if (nc_def_var(ncid, VAR_FLOAT_NAME, NC_FLOAT, 2, dimids, &float_varid)) ERR;
+      if (nc_def_var(ncid, VAR_DOUBLE_NAME, NC_DOUBLE, 2, dimids, &double_varid)) ERR;
+      if ((ret = nc_def_var_zstandard(ncid, float_varid, 4)))
+      {
+	  printf("error: %s\n", nc_strerror(ret));
+	  ERR;
+      }
+      if (nc_def_var_zstandard(ncid, double_varid, 4)) ERR;
+      if (nc_put_var_float(ncid, float_varid, (float *)float_out)) ERR;
+      if (nc_put_var_double(ncid, double_varid, (double *)double_out)) ERR;
+      if (nc_close(ncid)) ERR;
+
+      /* Open the file and make sure nc_inq_varids yields correct
+       * result. */
+      if (nc_open(FILE_NAME, NC_NOWRITE, &ncid)) ERR;
+      if (nc_inq_varids(ncid, &nvars_in, varids_in)) ERR;
+      if (nvars_in != 2 || varids_in[0] != 0 || varids_in[1] != 1) ERR;
+      if (nc_get_var_float(ncid, float_varid, (float *)float_in)) ERR;
+      if (nc_get_var_double(ncid, double_varid, (double *)double_in)) ERR;
+      for (i = 0; i < DIM1_LEN; i++)
+      {
+          for (j = 0; j < DIM2_LEN; j++)
+          {
+              if (float_in[i][j] != float_out[i][j]) ERR;
+              if (double_in[i][j] != double_out[i][j]) ERR;
+          }
+      }
+          
+      
+      if (nc_close(ncid)) ERR;
+   }
+
+   SUMMARIZE_ERR;
+   SUMMARIZE_ERR;
+
+   FINAL_RESULTS;
+}
diff --git a/nczarr_test/run_interop.sh b/nczarr_test/run_interop.sh
index e7a22f9ba7..b0cb1690fd 100755
--- a/nczarr_test/run_interop.sh
+++ b/nczarr_test/run_interop.sh
@@ -45,7 +45,7 @@ testcasezip() {
 }
 
 testcases3() {
-  set -x
+  #set -x
   echo "	o Running S3 Testcase:	$1	$2"
   zext=s3
   base=$1