what is an open source operating system code example

Example: what is open source

originally referred to open source software 
designed to be publicly accessible—anyone can 
see, modify, and distribute the code as they see fit.
is developed in a decentralized and collaborative way, 
relies on peer review and community production as such is 
cheaper, flexible, longevity than its proprietary peers 
not dependent on a single author or company.

value decentralized production and creativity.