diff --git a/NOTES b/NOTES
new file mode 100644
--- /dev/null
+++ b/NOTES
@@ -0,0 +1,69 @@
+Steps
+=====
+
+1. Set up mongrel_cluster
+
+follow: http://mongrel.rubyforge.org/docs/mongrel_cluster.html
+
+run it with user ioi:ioi
+
+
+2. Set up Apache
+
+in general follow: 
+http://mongrel.rubyforge.org/docs/apache.html
+
+2.1 enable mods
+
+run:
+sudo a2enmod rewrite
+sudo a2enmod proxy
+sudo a2enmod proxy_balancer
+sudo a2enmod proxy_http
+sudo a2enmod deflate
+sudo a2enmod headers
+
+2.2 edit virtual host at /etc/apache2/site-(available|enabled)
+
+added:
+===========================================
+<directory "/home/ioi/web_grader/public/">
+  Options FollowSymLinks
+  AllowOverride None
+  Order allow,deny
+  Allow from all
+</directory>
+
+<proxy balancer://mongrel_cluster>
+  BalancerMember http://127.0.0.1:8000
+  BalancerMember http://127.0.0.1:8001
+  BalancerMember http://127.0.0.1:8002
+  BalancerMember http://127.0.0.1:8003
+  BalancerMember http://127.0.0.1:8004
+  Allow from localhost
+</proxy>
+
+# can't use proxypass because we want access to balancer-manager
+#ProxyPass / balancer://mongrel_cluster/
+#ProxyPassReverse / balancer://mongrel_cluster/
+
+<Location /balancer-manager>
+  SetHandler balancer-manager
+</Location>
+
+RewriteEngine On
+
+# Uncomment for rewrite debugging
+RewriteLog "/var/log/apache2/ioi_rewrite.log"
+RewriteLogLevel 9
+
+# Rewrite to check for Rails cached page
+RewriteRule ^([^.]+)$ $1.html [QSA]
+
+# Redirect all non-static requests to cluster
+RewriteCond %{REQUEST_URI} !^/balancer-manager/(.*)$
+RewriteCond %{DOCUMENT_ROOT}/%{REQUEST_FILENAME} !-f
+RewriteRule ^/(.*)$ balancer://mongrel_cluster%{REQUEST_URI} [P,QSA,L]
+===========================================
+
+
diff --git a/app/views/main/list.rhtml b/app/views/main/list.rhtml
--- a/app/views/main/list.rhtml
+++ b/app/views/main/list.rhtml
@@ -22,6 +22,7 @@
   <div class="problist-each">
   <div class="probname">
     <%= "#{i+1}: #{p.full_name} (#{p.name})" %>
+    <%= link_to '[task description]', p.url if p.url!=nil %>
   </div>
   <div class="subinfo">
     <%= format_submission(@prob_submissions[i][1],
diff --git a/app/views/problems/_form.rhtml b/app/views/problems/_form.rhtml
--- a/app/views/problems/_form.rhtml
+++ b/app/views/problems/_form.rhtml
@@ -13,6 +13,9 @@
 <p><label for="problem_date_added">Date added</label><br/>
 <%= date_select 'problem', 'date_added'  %></p>
 
+<p><label for="problem_url">URL</label><br/>
+<%= text_field 'problem', 'url'  %></p>
+
 <p><label for="problem_available">Available</label><br/>
 <%= select("problem","available",[['True',true],['False',false]]) %></p>
 <!--[eoform:problem]-->
diff --git a/db/migrate/013_add_url_to_problem.rb b/db/migrate/013_add_url_to_problem.rb
new file mode 100644
--- /dev/null
+++ b/db/migrate/013_add_url_to_problem.rb
@@ -0,0 +1,9 @@
+class AddUrlToProblem < ActiveRecord::Migration
+  def self.up
+    add_column :problems, :url, :string
+  end
+
+  def self.down
+    remove_column :problems, :url
+  end
+end
diff --git a/db/schema.rb b/db/schema.rb
--- a/db/schema.rb
+++ b/db/schema.rb
@@ -9,7 +9,7 @@
 #
 # It's strongly recommended to check this file into your version control system.
 
-ActiveRecord::Schema.define(:version => 12) do
+ActiveRecord::Schema.define(:version => 13) do
 
   create_table "languages", :force => true do |t|
     t.string "name",        :limit => 10
@@ -23,6 +23,7 @@
     t.integer "full_score"
     t.date    "date_added"
     t.boolean "available"
+    t.string  "url"
   end
 
   create_table "rights", :force => true do |t|