containers.md

-Containers are a solution to provide your software, library, ... in an isolated environment.
+Containers are a solution to provide your software, library, etc., in an isolated environment.
 
-On atlas we provide these container software:
+On atlas we provide singularity as a container software.
 
-- docker
-- singularity (recommended)
+# Prerequisites
 
-To use docker, you have to ask an account to system administrators, but we recommend to use singularity whenever it is possible.
+Singularity documentation is available at <http://singularity.lbl.gov/> and should be the reference documentation.
 
-# Preriquisites
-
-Up to date docker and singularity documentation is available at 
-
-* https://www.docker.com/
-* http://singularity.lbl.gov/
-
-and should be the reference documentation.
-
-# Singularity.
-
-Singularity is installed as a ubuntu package now. You do not need to load any modules anymore.
+# Singularity
 
 To work with singularity, you have to download/create a singularity image (containing every software you need).
 To create a new image, see the [official documentation](http://singularity.lbl.gov/create-image).