diff --git m4/gtkdoc_jh_check_xml_catalog.m4 m4/gtkdoc_jh_check_xml_catalog.m4
new file mode 100644
index 0000000..618c1c9
--- /dev/null
+++ m4/gtkdoc_jh_check_xml_catalog.m4
@@ -0,0 +1,16 @@
+dnl Checks if a particular URI appears in the XML catalog
+dnl Usage:
+dnl	JH_CHECK_XML_CATALOG(URI, [FRIENDLY-NAME], [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+AC_DEFUN([JH_CHECK_XML_CATALOG],
+[
+	AC_REQUIRE([JH_PATH_XML_CATALOG],[JH_PATH_XML_CATALOG(,[:])])dnl
+	AC_MSG_CHECKING([for ifelse([$2],,[$1],[$2]) in XML catalog])
+	if $jh_found_xmlcatalog && \
+		AC_RUN_LOG([$XMLCATALOG --noout "$XML_CATALOG_FILE" "$1" >&2]); then
+		AC_MSG_RESULT([found])
+		ifelse([$3],,,[$3])
+	else
+		AC_MSG_RESULT([not found])
+		ifelse([$4],,[AC_MSG_ERROR([could not find ifelse([$2],,[$1],[$2]) in XML catalog])],[$4])
+	fi
+])
diff --git m4/gtkdoc_jh_path_xml_catalog.m4 m4/gtkdoc_jh_path_xml_catalog.m4
new file mode 100644
index 0000000..1618906
--- /dev/null
+++ m4/gtkdoc_jh_path_xml_catalog.m4
@@ -0,0 +1,34 @@
+dnl Checks the location of the XML Catalog
+dnl Usage:
+dnl	JH_PATH_XML_CATALOG([ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND])
+dnl Defines XMLCATALOG and XML_CATALOG_FILE substitutions
+AC_DEFUN([JH_PATH_XML_CATALOG],
+[
+	dnl check for the presence of the XML catalog
+	AC_ARG_WITH([xml-catalog],
+		AS_HELP_STRING([--with-xml-catalog=CATALOG],
+		[path to xml catalog to use]),,
+		[with_xml_catalog=/etc/xml/catalog])
+	jh_found_xmlcatalog=true
+	XML_CATALOG_FILE="$with_xml_catalog"
+	AC_SUBST([XML_CATALOG_FILE])
+	AC_MSG_CHECKING([for XML catalog ($XML_CATALOG_FILE)])
+	if test -f "$XML_CATALOG_FILE"; then
+		AC_MSG_RESULT([found])
+	else
+		jh_found_xmlcatalog=false
+		AC_MSG_RESULT([not found])
+	fi
+
+	dnl check for the xmlcatalog program
+	AC_PATH_PROG(XMLCATALOG, xmlcatalog, no)
+	if test "x$XMLCATALOG" = xno; then
+		jh_found_xmlcatalog=false
+	fi
+
+	if $jh_found_xmlcatalog; then
+		ifelse([$1],,[:],[$1])
+	else
+		ifelse([$2],,[AC_MSG_ERROR([could not find XML catalog])],[$2])
+	fi
+])
