diff --git a/index.html b/index.html
index decea87d6..b053de68b 100644
--- a/index.html
+++ b/index.html
@@ -29,9 +29,9 @@
     <ul class="mb-2">
       <li><a href="https://www.youtube.com/watch?v=x1LFbDQhbso">Google Tech Talk</a></li>
       <li>
-        <a href="http://cloud.grammaticalframework.org/">
+        <a href="//cloud.grammaticalframework.org/">
           GF Cloud
-          <img src="http://www.grammaticalframework.org/src/www/P/gf-cloud.png" style="height:30px" class="ml-2" alt="Cloud logo">
+          <img src="src/www/P/gf-cloud.png" style="height:30px" class="ml-2" alt="Cloud logo">
         </a>
       </li>
       <li>
@@ -83,7 +83,7 @@
       <li><a href="http://groups.google.com/group/gf-dev">Mailing List</a></li>
       <li><a href="https://github.com/GrammaticalFramework/gf-core/issues">Issue Tracker</a></li>
       <li><a href="doc/gf-people.html">Authors</a></li>
-      <li><a href="http://school.grammaticalframework.org/2018/">Summer School</a></li>
+      <li><a href="//school.grammaticalframework.org/2018/">Summer School</a></li>
     </ul>
     <a href="https://github.com/GrammaticalFramework/" class="btn btn-primary ml-3">
       <i class="fab fa-github mr-1"></i>
@@ -152,9 +152,9 @@ least one, it may help you to get a first idea of what GF is.
     <h2>Applications & Availability</h2>
     <p>
     GF can be used for building
-    <a href="http://cloud.grammaticalframework.org/translator/">translation systems</a>,
-    <a href="http://cloud.grammaticalframework.org/minibar/minibar.html">multilingual web gadgets</a>,
-    <a href="http://www.cs.chalmers.se/~hallgren/Alfa/Tutorial/GFplugin.html">natural-language interfaces</a>,
+    <a href="//cloud.grammaticalframework.org/translator/">translation systems</a>,
+    <a href="//cloud.grammaticalframework.org/minibar/minibar.html">multilingual web gadgets</a>,
+    <a href="http://www.cse.chalmers.se/~hallgren/Alfa/Tutorial/GFplugin.html">natural-language interfaces</a>,
     <a href="http://www.youtube.com/watch?v=1bfaYHWS6zU">dialogue systems</a>, and
     <a href="lib/doc/synopsis/index.html">natural language resources</a>.
     </p>
@@ -210,7 +210,7 @@ least one, it may help you to get a first idea of what GF is.
     <p>
     We run the IRC channel <strong><code>#gf</code></strong> on the Freenode network, where you are welcome to look for help with small questions or just start a general discussion.
     You can <a href="https://webchat.freenode.net/?channels=gf">open a web chat</a>
-    or <a href="http://www.grammaticalframework.org/irc/">browse the channel logs</a>.
+    or <a href="/irc/">browse the channel logs</a>.
     </p>
     <p>
     If you have a larger question which the community may benefit from, we recommend you ask it on the <a href="http://groups.google.com/group/gf-dev">mailing list</a>.
@@ -224,7 +224,7 @@ least one, it may help you to get a first idea of what GF is.
     <dl class="row">
       <dt class="col-sm-3 text-center text-nowrap">2018-12-03</dt>
       <dd class="col-sm-9">
-        <a href="http://school.grammaticalframework.org/2018/">Sixth GF Summer School</a> in Stellenbosch (South Africa), 3–14 December 2018
+        <a href="//school.grammaticalframework.org/2018/">Sixth GF Summer School</a> in Stellenbosch (South Africa), 3–14 December 2018
       </dd>
       <dt class="col-sm-3 text-center text-nowrap">2018-12-02</dt>
       <dd class="col-sm-9">
@@ -248,7 +248,7 @@ least one, it may help you to get a first idea of what GF is.
         GF is moving to <a href="https://github.com/GrammaticalFramework/GF/">GitHub</a>.</dd>
       <dt class="col-sm-3 text-center text-nowrap">2017-03-13</dt>
       <dd class="col-sm-9">
-        <a href="http://school.grammaticalframework.org/2017/">GF Summer School</a> in Riga (Latvia), 14-25 August 2017
+        <a href="//school.grammaticalframework.org/2017/">GF Summer School</a> in Riga (Latvia), 14-25 August 2017
       </dd>
     </dl>
 
@@ -268,7 +268,7 @@ least one, it may help you to get a first idea of what GF is.
     </p>
     <ul>
     <li>
-      <a href="http://www.cs.chalmers.se/~hallgren/Alfa/Tutorial/GFplugin.html">GF-Alfa</a>:
+      <a href="http://www.cse.chalmers.se/~hallgren/Alfa/Tutorial/GFplugin.html">GF-Alfa</a>:
       natural language interface to formal proofs
     </li>
     <li>
@@ -293,11 +293,11 @@ least one, it may help you to get a first idea of what GF is.
       <a href="http://www.cse.chalmers.se/alumni/markus/FM/">Functional Morphology</a>
     </li>
     <li>
-      <a href="http://www.molto-project.eu">MOLTO</a>:
+      <a href="//www.molto-project.eu">MOLTO</a>:
       multilingual online translation
     </li>
     <li>
-      <a href="http://remu.grammaticalframework.org">REMU</a>:
+      <a href="//remu.grammaticalframework.org">REMU</a>:
       reliable multilingual digital communication
     </li>
     </ul>