diff --git a/.gitignore b/.gitignore
index d12c03ec..bf1f70e4 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
 /Makefile.in
 .DS_Store
-*.xpi
\ No newline at end of file
+*-fx.xpi
+install.rdf
diff --git a/Makefile b/Makefile
index 95d18fea..53b92cae 100644
--- a/Makefile
+++ b/Makefile
@@ -2,16 +2,26 @@ all: Makefile.in
 
 -include Makefile.in
 
-RELEASE:=$(shell grep em:version install.rdf | head -n 1 | sed -e 's/ *<em:version>//' -e 's/<\/em:version>//')
+RELEASE:=$(shell xsltproc version.xsl install.xml)
 
-zotfile.xpi: FORCE
+zotfile-fx.xpi: FORCE
 	rm -rf $@
+	xsltproc removeupdateurl.xsl install.xml > install.rdf
 	zip -r $@ chrome chrome.manifest defaults install.rdf -x \*.DS_Store
 
-zotfile-%-fx.xpi: zotfile.xpi
+zotfile-github.xpi: FORCE
+	rm -rf $@
+	cp install.xml install.rdf
+	xsltproc -stringparam release ${RELEASE} update.xsl install.xml > update.rdf
+	zip -r $@ chrome chrome.manifest defaults install.rdf
+
+zotfile-%-fx.xpi: zotfile-fx.xpi
+	mv $< $@
+
+zotfile-%-github.xpi: zotfile-github.xpi
 	mv $< $@
 
-Makefile.in: install.rdf
-	echo "all: zotfile-${RELEASE}-fx.xpi" > Makefile.in
+Makefile.in: install.xml
+	echo "all: zotfile-${RELEASE}-fx.xpi zotfile-${RELEASE}-github.xpi" > Makefile.in
 
 FORCE:
diff --git a/install.rdf b/install.xml
similarity index 95%
rename from install.rdf
rename to install.xml
index 645e5604..57dbc3ab 100644
--- a/install.rdf
+++ b/install.xml
@@ -63,5 +63,6 @@
     <em:creator>Joscha Legewie</em:creator>
     <em:homepageURL>http://www.zotfile.com</em:homepageURL>
     <em:optionsURL>chrome://zotfile/content/options.xul</em:optionsURL>
+    <em:updateURL>https://raw.githubusercontent.com/jlegewie/zotfile/master/update.rdf</em:updateURL>
   </Description>
 </RDF>
diff --git a/removeupdateurl.xsl b/removeupdateurl.xsl
new file mode 100644
index 00000000..95c93181
--- /dev/null
+++ b/removeupdateurl.xsl
@@ -0,0 +1,13 @@
+<xsl:stylesheet version="1.0"
+ xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+ xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+
+<xsl:output omit-xml-declaration="yes"/>
+  <xsl:template match="node()|@*">
+    <xsl:copy>
+      <xsl:apply-templates select="node()|@*"/>
+    </xsl:copy>
+  </xsl:template>
+
+  <xsl:template match="em:updateURL"/>
+</xsl:stylesheet>
diff --git a/update.rdf b/update.rdf
new file mode 100644
index 00000000..5299cceb
--- /dev/null
+++ b/update.rdf
@@ -0,0 +1,32 @@
+<?xml version="1.0"?>
+<RDF:RDF xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+  <RDF:Description about="urn:mozilla:extension:zotfile@columbia.edu">
+    <em:updates>
+      <RDF:Seq>
+        <RDF:li>
+          <RDF:Description>
+            <em:version>3.3</em:version>
+            <em:targetApplication>
+              <RDF:Description>
+                <em:id>{ec8030f7-c20a-464f-9b0e-13a3a9e97384}</em:id>
+                <em:minVersion>18.*</em:minVersion>
+                <em:maxVersion>28.*</em:maxVersion>
+                <em:updateLink>https://raw.githubusercontent.com/jlegewie/zotfile/master/zotfile-3.3-github.xpi</em:updateLink>
+                <em:updateInfoURL>https://github.com/jlegewie/zotfile</em:updateInfoURL>
+              </RDF:Description>
+            </em:targetApplication>
+            <em:targetApplication>
+              <RDF:Description>
+                <em:id>zotero@chnm.gmu.edu</em:id>
+                <em:minVersion>3.0b1</em:minVersion>
+                <em:maxVersion>4.*</em:maxVersion>
+                <em:updateLink>https://raw.githubusercontent.com/jlegewie/zotfile/master/zotfile-3.3-github.xpi</em:updateLink>
+                <em:updateInfoURL>https://github.com/jlegewie/zotfile</em:updateInfoURL>
+              </RDF:Description>
+            </em:targetApplication>
+          </RDF:Description>
+        </RDF:li>
+      </RDF:Seq>
+    </em:updates>
+  </RDF:Description>
+</RDF:RDF>
diff --git a/update.xsl b/update.xsl
new file mode 100644
index 00000000..816aebf7
--- /dev/null
+++ b/update.xsl
@@ -0,0 +1,47 @@
+<?xml version="1.0"?>
+
+<xsl:stylesheet version="1.0"
+  xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
+  xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#"
+  xmlns:em="http://www.mozilla.org/2004/em-rdf#"
+  >
+<xsl:output method="xml" indent="yes"/>
+
+<xsl:template match="/">
+  <RDF:RDF xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#">
+    <xsl:variable name="id" select="RDF:RDF/RDF:Description/em:id"/>
+    <xsl:variable name="version" select="RDF:RDF/RDF:Description/em:version"/>
+    <RDF:Description about="urn:mozilla:extension:{$id}">
+      <em:updates>
+        <RDF:Seq>
+          <RDF:li>
+            <RDF:Description>
+              <em:version><xsl:value-of select="$version"/></em:version>
+              <xsl:for-each select="RDF:RDF/RDF:Description/em:targetApplication">
+                <em:targetApplication>
+                  <RDF:Description>
+                    <xsl:if test="string-length(RDF:Description/em:id)!=0">
+                      <em:id><xsl:value-of select="RDF:Description/em:id"/></em:id>
+                    </xsl:if>
+                    <xsl:if test="string-length(RDF:Description/em:minVersion)!=0">
+                      <em:minVersion><xsl:value-of select="RDF:Description/em:minVersion"/></em:minVersion>
+                    </xsl:if>
+                    <xsl:if test="string-length(RDF:Description/em:maxVersion)!=0">
+                      <em:maxVersion><xsl:value-of select="RDF:Description/em:maxVersion"/></em:maxVersion>
+                    </xsl:if>
+
+                    <em:updateLink>https://raw.githubusercontent.com/jlegewie/zotfile/master/zotfile-<xsl:value-of select="$release"/>-github.xpi</em:updateLink>
+
+                    <em:updateInfoURL>https://github.com/jlegewie/zotfile</em:updateInfoURL>
+                  </RDF:Description>
+                </em:targetApplication>
+              </xsl:for-each>
+            </RDF:Description>
+          </RDF:li>
+        </RDF:Seq>
+      </em:updates>
+    </RDF:Description>
+  </RDF:RDF>
+</xsl:template>
+
+</xsl:stylesheet>
diff --git a/version.xsl b/version.xsl
new file mode 100644
index 00000000..9718facd
--- /dev/null
+++ b/version.xsl
@@ -0,0 +1,7 @@
+<?xml version="1.0"?>
+<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform" xmlns:RDF="http://www.w3.org/1999/02/22-rdf-syntax-ns#" xmlns:em="http://www.mozilla.org/2004/em-rdf#" >
+<xsl:output method="text"/>
+
+<xsl:template match="/"><xsl:value-of select="RDF:RDF/RDF:Description/em:version"/></xsl:template>
+
+</xsl:stylesheet>
\ No newline at end of file