Open Source Training Cloud Foundry open sourced their curriculum to train students on how to use it. Are there any other open source courses out there or organizations who collects training that is open sourced? 

To clarify: I am looking for training for hardware/software that has been open sourced. Not open source software that has training.
First, there is a scientific journal that may include publications of such material that are what you are looking for: The Journal of Open Source Education, "An educator friendly journal for publishing computational learning modules and educational software."

Second, but I am not sure this is completely relevant to your question, there are the open source computational lesson from The Carpentries:


Software Carpentry has lessons on the unix shell, version control (git and mercurial), programming in Python or R, R for Reproducible Scientific Analysis and more
Data Carpentry has lessons more tailored to a research domain, on data analysis, but includes programming as well
not yet part of The Carpentries, but under development is HPC carpentry lessons: shell, Python, Chapel, Snakemake
there is also Library Carpentry, but their lessons are more tailored to librarians


All these lessons are CC-BY.

Disclaimer: I am on The Carpentries Executive Council