diff --git a/Gemfile b/Gemfile
index 8dbac14..bcbd9f2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,4 +1,5 @@
 source "http://rubygems.org"
 gem "rake"
 gem "jekyll"
+gem "gsl"
 gem "susy"
diff --git a/Gemfile.lock b/Gemfile.lock
index f06c113..0ee0032 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -1,60 +1,61 @@
 GEM
   remote: http://rubygems.org/
   specs:
-    chunky_png (1.2.9)
-    classifier (1.3.3)
+    blankslate (2.1.2.4)
+    classifier (1.3.4)
       fast-stemmer (>= 1.0.0)
     colorator (0.1)
-    commander (4.1.5)
+    commander (4.1.6)
       highline (~> 1.6.11)
-    compass (0.12.2)
-      chunky_png (~> 1.2)
-      fssm (>= 0.2.7)
-      sass (~> 3.1)
     fast-stemmer (1.0.2)
     ffi (1.9.3)
-    fssm (0.2.10)
-    highline (1.6.20)
-    jekyll (1.3.0)
+    gsl (1.15.3)
+      narray (>= 0.5.9)
+    highline (1.6.21)
+    jekyll (1.4.3)
       classifier (~> 1.3)
       colorator (~> 0.1)
       commander (~> 4.1.3)
-      liquid (~> 2.5.2)
+      liquid (~> 2.5.5)
       listen (~> 1.3)
-      maruku (~> 0.6.0)
+      maruku (~> 0.7.0)
       pygments.rb (~> 0.5.0)
       redcarpet (~> 2.3.0)
       safe_yaml (~> 0.9.7)
-    liquid (2.5.3)
+      toml (~> 0.1.0)
+    liquid (2.5.5)
     listen (1.3.1)
       rb-fsevent (>= 0.9.3)
       rb-inotify (>= 0.9)
       rb-kqueue (>= 0.2)
-    maruku (0.6.1)
-      syntax (>= 1.0.0)
-    posix-spawn (0.3.6)
+    maruku (0.7.1)
+    narray (0.6.0.8)
+    parslet (1.5.0)
+      blankslate (~> 2.0)
+    posix-spawn (0.3.8)
     pygments.rb (0.5.4)
       posix-spawn (~> 0.3.6)
       yajl-ruby (~> 1.1.0)
-    rake (10.1.0)
-    rb-fsevent (0.9.3)
-    rb-inotify (0.9.2)
+    rake (10.1.1)
+    rb-fsevent (0.9.4)
+    rb-inotify (0.9.3)
       ffi (>= 0.5.0)
-    rb-kqueue (0.2.0)
+    rb-kqueue (0.2.2)
       ffi (>= 0.5.0)
     redcarpet (2.3.0)
     safe_yaml (0.9.7)
-    sass (3.2.12)
-    susy (1.0.9)
-      compass (>= 0.12.2)
-      sass (>= 3.2.0)
-    syntax (1.0.0)
+    sass (3.3.2)
+    susy (2.1.1)
+      sass (~> 3.3.0)
+    toml (0.1.1)
+      parslet (~> 1.5.0)
     yajl-ruby (1.1.0)
 
 PLATFORMS
   ruby
 
 DEPENDENCIES
+  gsl
   jekyll
   rake
   susy
diff --git a/_config.yml b/_config.yml
index 318beae..41f8845 100644
--- a/_config.yml
+++ b/_config.yml
@@ -4,7 +4,7 @@ description: "James Walker is an independent developer and hacker"
 url: http://walkah.net
 
 pygments: true
-lsi: false
+lsi: true
 markdown: redcarpet
 permalink: blog/:title
 exclude: 
diff --git a/_layouts/post.html b/_layouts/post.html
index b7a8692..d4d9d3c 100644
--- a/_layouts/post.html
+++ b/_layouts/post.html
@@ -5,3 +5,9 @@ layout: default
 {% include post.html %}
 
 {% include vcard.html %}
+
+<h3>related posts</h3>
+{% for post in site.related_posts limit:5 %}
+  {% include article_list.html %}
+{% endfor %}
+