add cloud info

CloudComputing_Lab/modules/ROOT/pages/tech-list.adoc

@@ -18,11 +18,10 @@ TIP: Why Open Source!
 
 video::a8fHgx9mE5U[youtube, start=0]
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-Open source refers to an openly distributed program code (including codes that are *free of charge*) that can be *utilized* and *modified* by the end user *without restriction.*
+Open source refers to an *openly distributed* program code (including codes that are *free of charge*) that can be *utilized* and *modified* by the end user *without restriction.*
 ====
 
 
-
 == Docker
 
 * https://www.cloudbees.com/blog/why-docker[Docker^]
@@ -39,6 +38,24 @@ Open source refers to an openly distributed program code (including codes that a
 
 * https://docker-curriculum.com/[HowTo]
 
+== Alternatives to Docker
+
+TIP: https://apptainer.org/docs/admin/main/[Apptainer/Singularity] - Best Container system for HPC
+
+====
+Singularity can be used with Docker images. This feature was included because developers use and really like using Docker and scientists have already put much resources into creating Docker images. 
+
+Features:
+
+* Use a Docker image instantly as a Singularity image
+* Pull a Docker image
+* Build images with bases from assembled Docker layers
+
+====
+
+
+
+
 == Next Step DockerSwarm
 
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