Index: lucene/build.xml
===================================================================
--- lucene/build.xml	(revision 1328893)
+++ lucene/build.xml	(working copy)
@@ -184,11 +184,11 @@
   </target>
 
   <target name="documentation" description="Generate all documentation"
-    depends="javadocs,changes-to-html,doc-index"/>
+    depends="javadocs,changes-to-html,process-webpages"/>
   <target name="javadoc" depends="javadocs"/>
   <target name="javadocs" description="Generate javadoc" depends="javadocs-lucene-core, javadocs-modules, javadocs-test-framework"/>
   
-  <target name="doc-index">
+  <target name="process-webpages" depends="resolve-pegdown">
     <pathconvert pathsep="|" dirsep="/" property="buildfiles">
       <fileset dir="." includes="**/build.xml" excludes="build.xml,analysis/*,build/**,tools/**,backwards/**,site/**"/>
     </pathconvert>
@@ -205,6 +205,12 @@
       <param name="buildfiles" expression="${buildfiles}"/>
       <param name="version" expression="${version}"/>
     </xslt>
+    
+    <pegdown todir="${javadoc.dir}">
+      <fileset dir="." includes="CHANGES.txt,README.txt,BUILD.txt,MIGRATE.txt,JRE_VERSION_MIGRATION.txt"/>
+      <globmapper from="*.txt" to="*.html"/>
+    </pegdown>
+
     <copy todir="${javadoc.dir}">
       <fileset dir="site/html" includes="**/*"/>
     </copy>
Index: lucene/common-build.xml
===================================================================
--- lucene/common-build.xml	(revision 1328893)
+++ lucene/common-build.xml	(working copy)
@@ -1506,4 +1506,61 @@
       </scp>
     </sequential>
   </macrodef>
+  
+  <!-- PEGDOWN macro: Before using depend on the target "resolve-pegdown" -->
+  
+  <target name="resolve-pegdown" unless="pegdown.loaded">
+    <ivy:cachepath organisation="org.pegdown" module="pegdown" revision="1.1.0"
+      inline="true" conf="default" type="jar" transitive="true" pathid="pegdown.classpath"/>
+    <property name="pegdown.loaded" value="true"/>
+  </target>
+  
+  <macrodef name="pegdown">
+    <attribute name="todir"/>
+    <attribute name="flatten" default="false"/>
+    <element name="nested" optional="false" implicit="true"/>
+    <sequential>
+      <copy todir="@{todir}" flatten="@{flatten}" encoding="UTF-8" outputencoding="UTF-8"
+        overwrite="true" verbose="true" preservelastmodified="false"
+      >
+        <filterchain>
+          <tokenfilter>
+            <filetokenizer/>
+            <replaceregex pattern="\b(LUCENE|SOLR)\-\d+\b" replace="[\0](https://issues.apache.org/jira/browse/\0)" flags="gs"/>
+            <scriptfilter language="javascript" classpathref="pegdown.classpath"><![CDATA[
+              importClass(java.util.regex.Pattern);
+              importClass(java.util.regex.Matcher);
+              importClass(org.pegdown.PegDownProcessor);
+              importClass(org.pegdown.Extensions);
+              importClass(org.pegdown.FastEncoder);
+              var markdownSource = self.getToken();
+              var title = undefined;
+              var matcher = Pattern.compile('^(#+\\s*)?(.+)[\\n\\r]').matcher(markdownSource);
+              if (matcher.find()) {
+                title = matcher.group(2);
+                if (matcher.group(1) == null || matcher.group(1).isEmpty()) {
+                  // Convert the first line into a markdown heading, if it is not already:
+                  markdownSource = '# ' + markdownSource;
+                }
+              }
+              var processor = new PegDownProcessor(
+                Extensions.ABBREVIATIONS | Extensions.AUTOLINKS |
+                Extensions.FENCED_CODE_BLOCKS | Extensions.SMARTS
+              );
+              var html = '<html>\n<head>\n';
+              if (title) {
+                html += '<title>' + FastEncoder.encode(title) + '</title>\n';
+              }
+              html += '<META http-equiv="Content-Type" content="text/html; charset=UTF-8">\n';
+              html += '</head>\n<body>\n';
+              html += processor.markdownToHtml(markdownSource);
+              html += '\n</body>\n</html>\n';
+              self.setToken(html);
+            ]]></scriptfilter>
+          </tokenfilter>
+        </filterchain>
+        <nested/>
+      </copy>
+    </sequential>
+  </macrodef>
 </project>
