diff --git a/3. business models.html b/3. business models.html
index a65a78c0904ff1211cb80504fe503c06c5f209e1..8e968ac4ecb31a4a3c59a6977b3719fd98975699 100644
--- a/3. business models.html	
+++ b/3. business models.html	
@@ -174,6 +174,11 @@ class: center, middle
 ---
 class: center, middle
 
+#Odoo
+
+---
+class: center, middle
+
 # JBoss
 - Bought by Red Hat
 - J2EE server
@@ -230,13 +235,23 @@ class: center, middle
 - Opensourced by Facebook - Google
 - Because it's not their main business
 
+---
+class: center, middle
+
+#Nokia and N770/N800/N810
+- Created a swarm of open-source companies
+- Collabora : diversified on GStreamer and now LibreOffice
+- Immendio/Lanedo : diversified on Samsung R\&D and LibreOffice
+
 
 ---
 class: center, middle
 
 #Advertising
 
+
 ???
+Often seen on Android
 
 https://medium.com/open-collective/using-ads-to-sustain-open-source-d048b75d4979
 
@@ -244,7 +259,7 @@ https://medium.com/open-collective/using-ads-to-sustain-open-source-d048b75d4979
 class: center, middle
 
 #Crowdfunding
-- Diaspora : 200.000$ on Kickstarter in 2010
+- Diaspora* : 200.000$ on Kickstarter in 2010
 
 ---
 class: center, middle
@@ -268,7 +283,6 @@ class: center, middle
 - Limited supply
 - No double spending
 - Fongibility
-
 - Then you need trust
 
 ---
@@ -301,6 +315,10 @@ class: center, middle
 ???
 If not opensource, it is not a true blockchain
 
+---
+class: center, middle
+background-image: url(https://github.com/ploum/lingi2401/raw/master/images/blockchain.png)
+
 
 ---
 class: center, middle
diff --git a/4. community.html b/4. community.html
new file mode 100644
index 0000000000000000000000000000000000000000..d905182a9ebdab4b6676f3efe0f80bd29a89fac6
--- /dev/null
+++ b/4. community.html	
@@ -0,0 +1,184 @@
+<!DOCTYPE html>
+<html>
+  <head>
+    <title>LINGI2401 - 4. Community</title>
+
+    <meta charset="utf-8">
+    <style>
+      @import url(https://fonts.googleapis.com/css?family=Yanone+Kaffeesatz);
+      @import url(https://fonts.googleapis.com/css?family=Droid+Serif:400,700,400italic);
+      @import url(https://fonts.googleapis.com/css?family=Ubuntu+Mono:400,700,400italic);
+
+      body { font-family: 'Droid Serif'; }
+      h1, h2, h3 {
+        font-family: 'Yanone Kaffeesatz';
+        font-weight: normal;
+      }
+      .remark-code, .remark-inline-code { font-family: 'Ubuntu Mono'; }
+    </style>
+  </head>
+  <body>
+    <textarea id="source">
+
+class: center, middle
+
+# LINGI 2401 : Open Source strategy for software development
+
+Lionel Dricot
+lionel.dricot@uclouvain.be
+lionel@ploum.net
+
+@ploum - @ploum@mamot.fr
+
+???
+
+
+---
+class: center, middle
+
+# One thing you learned from last week
+???
+Everybody should have a different one
+
+---
+class: center, middle
+
+#Calendar
+- October 9th : Xavier Damman, OpenCollective
+- October 23rd : Questions and work together on the project
+- November 6th : Thomas Lambot, rLoop  (from San Francisco through Skype)
+
+---
+class: center, middle
+
+#The code
+
+???
+Every Floss project, is by definition, centered around the code. The goal of the project is to produce some code.
+
+---
+class: center, middle
+
+#One question
+"Should this modification be part of the code or not?"
+
+---
+class: center, middle
+
+#Generalisation
+"Every human institation has one single goal: take decisions in the name of multiple individuals"
+
+???
+Our parliament decide "should this modification be part of the law?"
+
+---
+class: center, middle
+
+#Historical code management
+- Contributors send patches by mail (even snail mails) and the maintainer merge it.
+- Dictatorship by the maintainer (which might be good)
+- Linux was maintained that way until 2002
+- Lot of proprietary softwares still work that way in the industry
+
+---
+class: center, middle
+
+#First Revision control system
+- RVCS?  (à vérifier)
+- CVS
+- SVN
+
+???
+Centralised. User need an account to commit. You cannot do anything locally. Big commits. Branches only for existing developpers.
+
+---
+class: center, middle
+
+#Distributed Version Control System
+- Mercurial
+- Bazaar
+- Git
+
+???
+Story of git. War between the 3. Git seems to be the big winner.
+
+---
+class: center, middle
+
+#Interfaces to DVCS
+- Launchpad (bazaar)
+- Github (proprietary!)
+- Gitlab
+- Gitorious
+- Keybase : encrypted end-2-end git repositories
+
+---
+class: center, middle
+
+#Not everything is code
+- Need for a way to communicate
+- A way to store what is not code
+- Project management
+
+---
+class: center, middle
+
+#Wiki
+
+---
+class: center, middle
+
+#Communication channels
+- Mailing-lists (mailman)
+- IRC
+- Forum
+- XMPP chatrooms (Jabber)
+- Now Slack (proprietary)
+- Keybase (it's new!)
+
+---
+class: center, middle
+
+#Project management through bug trackers
+- Bugzilla
+- Launchpad
+- 
+
+???
+Lot of discussions happen there
+
+---
+class: center, middle
+
+#Trolls and bicycle sheding
+
+---
+class: center, middle
+
+#Fork
+
+---
+class: center, middle
+
+
+
+
+---
+class: center, middle
+# Discussion time
+
+
+
+
+
+
+
+
+    </textarea>
+    <script src="https://remarkjs.com/downloads/remark-latest.min.js">
+    </script>
+    <script>
+      var slideshow = remark.create();
+    </script>
+  </body>
+</html>
diff --git a/README.md b/README.md
index e081c8a35352a1e9ae6c83fe5402fc8b3cd9a94d..4c142f9a587737c0828e4af5721013d41ee85d39 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,11 @@
 # lingi2401
 Lingi2401 - Open Source strategy for software development
+
+Open each HMTL file in your browser. Press “P” to see the comments for each slides.
+
+Please contribute your notes to this course, as comments for the slides or even as separate notes. This will help students that cannot attend the course.
+
+##Calendar
+- October 9th : Xavier Damman, OpenCollective
+- October 23rd : Questions and work together on the project (optional)
+- November 6th : Thomas Lambot, rLoop  (from San Francisco through Skype)
\ No newline at end of file