diff --git a/VERSION b/VERSION
index 643711b8..8465a3b5 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.3.298
+8.3.299
diff --git a/calma/CalmaWrite.c b/calma/CalmaWrite.c
index 7657c046..d06325ee 100644
--- a/calma/CalmaWrite.c
+++ b/calma/CalmaWrite.c
@@ -943,12 +943,43 @@ calmaProcessDef(def, outf, do_library)
 	size_t defsize, numbytes;
 	off_t cellstart, cellend, structstart;
  	dlong cval;
+	int namelen;
+	char *modName;
 	FILE *fi;
 
+	/* Handle compressed files */
+	
+	modName = filename;
+	namelen = strlen(filename);
+	if ((namelen > 4) && !strcmp(filename + namelen - 3, ".gz"))
+	{
+	    char *sysCmd, sptr;
+	
+	    sptr = strrchr(filename, '/');
+	    if (sptr == NULL)
+		sptr = filename;
+	    else
+		sptr++;
+	
+	    modName = StrDup((char **)NULL, sptr);
+	    *(modName + strlen(modName) - 3) = '\0';
+
+	    sysCmd = mallocMagic(18 + namelen + strlen(modName));
+	    sprinf(sysCmd, "gunzip -c -k %s > %s", filename, modName);
+	    if (system(sysCmd) != 0)
+	    {
+		/* File didn't uncompress.  Go back to original name,
+		 * although that will probably fail and raise an error.
+		 */
+		freeMagic(modName);
+		modName = filename;
+	    }
+	}
+	
 	/* Use PaOpen() so the paths searched are the same as were	*/
 	/* searched to find the .mag file that indicated this GDS file.	*/
 
-	fi = PaOpen(filename, "r", "", Path, CellLibPath, &retfilename);
+	fi = PaOpen(modName, "r", "", Path, CellLibPath, &retfilename);
 	if (fi == NULL)
 	{
 	    /* This is a rare error, but if the subcell is inside	*/
@@ -964,7 +995,9 @@ calmaProcessDef(def, outf, do_library)
 
 	    TxError("Calma output error:  Can't find GDS file \"%s\" "
 				"for vendor cell \"%s\".  It will not be output.\n",
-				filename, def->cd_name);
+				modName, def->cd_name);
+
+	    if (modName != filename) freeMagic(modName);
 
 	    if (CalmaAllowUndefined)
 		return 0;
@@ -1112,6 +1145,17 @@ calmaProcessDef(def, outf, do_library)
 	    }
 	    fclose(fi);
 
+	    if (modName != filename)
+	    {
+		/* Remove the uncompressed file */
+		if (unlink(modName) != 0)
+		{
+		    TxError("Error attempting to delete uncompressed file \"%s\"\n",
+				modName);
+		}
+		freeMagic(modName);
+	    }
+
 	    /* Mark the definition as vendor GDS so that magic doesn't	*/
 	    /* try to generate subcell interaction or array interaction	*/
 	    /* paint for it.						*/
diff --git a/commands/CmdCD.c b/commands/CmdCD.c
index 114aacb9..44189c47 100644
--- a/commands/CmdCD.c
+++ b/commands/CmdCD.c
@@ -125,6 +125,9 @@ CmdCalma(w, cmd)
     char **msg, *namep, *dotptr;
     CellDef *rootDef;
     FILE *f;
+    int namelen;
+    bool gzipd;
+    char *realName, *saveName, *modName;
 
     extern int CalmaFlattenLimit;
 
@@ -870,11 +873,54 @@ CmdCalma(w, cmd)
 	case CALMA_READ:
 	    if (cmd->tx_argc != 3) goto wrongNumArgs;
 
+	    /* Check for compressed files, and uncompress them.	    	*/
+	    /* Always uncompress into the current working directory	*/
+	    /* because the original compressed file might be in an	*/
+	    /* unwriteable directory.					*/
+
+	    modName = cmd->tx_argv[2];
+	    namelen = strlen(modName);
+	    if ((namelen > 4) && !strcmp(modName + namelen - 3, ".gz"))
+	    {
+		char *sysCmd, *sptr;
+
+		/* First try to open the uncompressed file name.  If	*/
+		/* the file exists, then don't try to uncompress on top	*/
+		/* of it, but just fail.				*/
+
+		sptr = strrchr(modName, '/');
+		if (sptr == NULL)
+		    sptr = modName;
+		else
+		    sptr++;
+		modName = StrDup((char **)NULL, sptr);
+		*(modName + strlen(modName) - 3) = '\0';
+		if ((f = PaOpen(modName, "r", NULL, Path,
+		    	(char *)NULL, NULL)) != (FILE *)NULL)
+		{
+		    fclose(f);
+		    TxError("Uncompressed file \"%s\" already exists!\n", modName);
+		    freeMagic(modName);
+		    return;
+		}
+
+		sysCmd = mallocMagic(18 + namelen + strlen(modName));
+		/* Note: "-k" keeps the original compressed file */
+		TxPrintf("Uncompressing file \"%s\".\n", cmd->tx_argv[2]);
+		sprintf(sysCmd, "gunzip -c -k %s > %s", cmd->tx_argv[2], modName);
+		if (system(sysCmd) != 0)
+		{
+		    freeMagic(modName);
+		    modName = NULL;
+		}
+		freeMagic(sysCmd);
+	    }
+
 	    /* Check for various common file extensions, including	*/
 	    /* no extension (as-is), ".gds", ".gds2", and ".strm".	*/
 
 	    for (ext = 0; gdsExts[ext] != NULL; ext++)
-		if ((f = PaOpen(cmd->tx_argv[2], "r", gdsExts[ext], Path,
+		if ((f = PaOpen(modName, "r", gdsExts[ext], Path,
 		    	(char *) NULL, &namep)) != (FILE *)NULL)
 		    break;
 
@@ -887,6 +933,18 @@ CmdCalma(w, cmd)
 	    }
 	    CalmaReadFile(f, namep);
 	    (void) fclose(f);
+	    if (modName != cmd->tx_argv[2])
+	    {
+		/* A gzipped file was read and now the uncompressed	*/
+		/* file that was generated should be removed.		*/
+
+		if (unlink(namep) != 0)
+		{
+		    TxError("Error attempting to delete uncompressed file \"%s\"\n",
+				namep);
+		}
+		freeMagic(modName);
+	    }
 	    return;
     }
 
@@ -898,8 +956,20 @@ CmdCalma(w, cmd)
 outputCalma:
     dotptr = strrchr(namep, '.');
 
+    /* Check for additional ".gz" extension */
+    if (!strcmp(dotptr, ".gz"))
+    {
+	gzipd = TRUE;
+	*dotptr = '\0';
+    	dotptr = strrchr(namep, '.');
+    }
+    else
+	gzipd = FALSE;
+
     f = PaOpen(namep, "w", (dotptr == NULL) ? ".gds" : "", ".",
-		(char *) NULL, (char **) NULL);
+		(char *) NULL, (char **)&realName);
+    if (gzipd)
+	saveName = StrDup((char **)NULL, realName);
 
     if (f == (FILE *) NULL)
     {
@@ -914,6 +984,24 @@ outputCalma:
 	TxError("File may be incompletely written.\n");
     }
     (void) fclose(f);
+
+    if (gzipd)
+    {
+	char *sysCmd;
+	sysCmd = mallocMagic(16 + strlen(saveName));
+        TxPrintf("Compressing file \"%s\"\n", saveName);
+	sprintf(sysCmd, "gzip -n --best %s", saveName);
+
+	/* Note that without additional arguments, "gzip" will wholly	*/
+	/* replace the uncompressed file with the compressed one.	*/
+
+	if (system(sysCmd) != 0)
+	{
+	    TxError("Failed to compress file \"%s\"\n", saveName);
+	}
+	freeMagic(sysCmd);
+	freeMagic(saveName);
+    }
 }
 #endif
 
diff --git a/scripts/configure b/scripts/configure
index ddf28479..9ab0f802 100755
--- a/scripts/configure
+++ b/scripts/configure
@@ -672,6 +672,8 @@ X_PRE_LIBS
 X_CFLAGS
 XMKMF
 PYTHON3
+GUNZIP
+GZIP
 CSH
 GCORE
 EGREP
@@ -5327,6 +5329,103 @@ if test "x${CSH}" = "xno"; then
   as_fn_error $? "cannot find /bin/csh---cannot compile!" "$LINENO" 5
 fi
 
+# Extract the first word of "gzip", so it can be a program name with args.
+set dummy gzip; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_GZIP+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $GZIP in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_GZIP="$GZIP" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_GZIP="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_path_GZIP" && ac_cv_path_GZIP="no"
+  ;;
+esac
+fi
+GZIP=$ac_cv_path_GZIP
+if test -n "$GZIP"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $GZIP" >&5
+$as_echo "$GZIP" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+if test "x${GZIP}" = "xno"; then
+  as_fn_error $? "cannot find gzip---will not be able to compress large files" "$LINENO" 5
+else
+  $as_echo "#define HAVE_GZIP 1" >>confdefs.h
+
+fi
+
+# Extract the first word of "gunzip", so it can be a program name with args.
+set dummy gunzip; ac_word=$2
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
+$as_echo_n "checking for $ac_word... " >&6; }
+if ${ac_cv_path_GUNZIP+:} false; then :
+  $as_echo_n "(cached) " >&6
+else
+  case $GUNZIP in
+  [\\/]* | ?:[\\/]*)
+  ac_cv_path_GUNZIP="$GUNZIP" # Let the user override the test with a path.
+  ;;
+  *)
+  as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
+for as_dir in $PATH
+do
+  IFS=$as_save_IFS
+  test -z "$as_dir" && as_dir=.
+    for ac_exec_ext in '' $ac_executable_extensions; do
+  if as_fn_executable_p "$as_dir/$ac_word$ac_exec_ext"; then
+    ac_cv_path_GUNZIP="$as_dir/$ac_word$ac_exec_ext"
+    $as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
+    break 2
+  fi
+done
+  done
+IFS=$as_save_IFS
+
+  test -z "$ac_cv_path_GUNZIP" && ac_cv_path_GUNZIP="no"
+  ;;
+esac
+fi
+GUNZIP=$ac_cv_path_GUNZIP
+if test -n "$GUNZIP"; then
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: $GUNZIP" >&5
+$as_echo "$GUNZIP" >&6; }
+else
+  { $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
+$as_echo "no" >&6; }
+fi
+
+
+if test "x${GUNZIP}" = "xno"; then
+  as_fn_error $? "cannot find gunzip---will not be able to automatically uncompress files" "$LINENO" 5
+else
+  $as_echo "#define HAVE_GUNZIP 1" >>confdefs.h
+
+fi
+
+
 # Extract the first word of "python3", so it can be a program name with args.
 set dummy python3; ac_word=$2
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
diff --git a/scripts/configure.in b/scripts/configure.in
index 2d0558b0..ddd4a9d8 100644
--- a/scripts/configure.in
+++ b/scripts/configure.in
@@ -285,6 +285,23 @@ if test "x${CSH}" = "xno"; then
   AC_MSG_ERROR([cannot find /bin/csh---cannot compile!])
 fi
 
+dnl gzip and gunzip are used for file compression and uncompression of
+dnl large files (e.g., GDS)
+AC_PATH_PROG([GZIP], [gzip], [no])
+if test "x${GZIP}" = "xno"; then
+  AC_MSG_ERROR([cannot find gzip---will not be able to compress large files])
+else
+  AC_DEFINE(HAVE_GZIP)
+fi
+
+AC_PATH_PROG([GUNZIP], [gunzip], [no])
+if test "x${GUNZIP}" = "xno"; then
+  AC_MSG_ERROR([cannot find gunzip---will not be able to automatically uncompress files])
+else
+  AC_DEFINE(HAVE_GUNZIP)
+fi
+
+
 dnl Python3 is preferred for running the preprocessor script
 dnl but CPP can be used instead.
 AC_PATH_PROG([PYTHON3], [python3], [no])
diff --git a/utils/utils.h b/utils/utils.h
index 3f1b481c..6f69266c 100644
--- a/utils/utils.h
+++ b/utils/utils.h
@@ -44,6 +44,7 @@ extern int LookupStructFull();
 extern int PaExpand(char **, char **, int);
 extern char *nextName();
 extern FILE *PaOpen(char *, char *, char *, char *, char *, char **);
+extern FILE *PaZOpen(char *, char *, char *, char *, char *, char **, bool *);
 extern FILE *PaLockOpen(char *, char *, char *, char *, char *, char **, bool *);
 extern char *StrDup(char **, char *);
 extern int Match();