Use stylesheet transformations to output HTML, for example

src/xslt.c

@@ -0,0 +1,29 @@
+#include <string.h>
+#include <libxml/tree.h>
+#include <libxslt/xslt.h>
+#include <libxslt/transform.h>
+#include "options.h"
+
+xmlDocPtr
+applyStyleSheet(xmlDocPtr document, const char* styleSheetName) {
+    int l = strlen(styleSheetName) + 5;
+    char *t = malloc(l), *styleSheetFileName = NULL;
+    xsltStylesheetPtr xsl = NULL;
+    xmlDocPtr res = NULL;
+
+    strlcpy(t, styleSheetName, l);
+    strlcat(t, ".xsl", l);
+    styleSheetFileName = OptionsDataFile(t);
+    free(t);
+    fprintf(stderr, "Loading stylesheet %s ...\n", styleSheetFileName);
+
+    xmlSubstituteEntitiesDefault(1);
+    xmlLoadExtDtdDefaultValue = 1;
+    xsl = xsltParseStylesheetFile(styleSheetFileName);
+    res = xsltApplyStylesheet(xsl, document, NULL);
+
+    free(styleSheetFileName);
+    xsltFreeStylesheet(xsl);
+
+    return res;
+}