diff --git a/DockerSwarm/exercise.adoc b/DockerSwarm/exercise.adoc
index 98a4c6f..608e044 100644
--- a/DockerSwarm/exercise.adoc
+++ b/DockerSwarm/exercise.adoc
@@ -164,6 +164,10 @@ image:swarmlab-network.png[alt="Vlab Network"]
 ** https://github.com/emfloyd2/docker-graphviz
 ** https://github.com/omerio/graphviz-server
 
+=== collaboration platform 
+* Nextdloud (similar to Dropbox, Office 365 or Google Drive) - https://en.wikipedia.org/wiki/Nextcloud, 
+**   https://github.com/nextcloud/docker/tree/63438ef792fdedd4ceb80664d22391aca21f6bd1
+** https://github.com/nextcloud/docker
 
 == Q&A
 [qanda]