This document provides an overview of the open Software Assurance Maturity Model (openSAMM). It explains that openSAMM is an open framework to help organizations formulate and implement a strategy for software security tailored to their specific risks. It describes openSAMM's four business functions and three security practices for each function. It outlines openSAMM's maturity levels and the objectives, activities, results, and metrics defined for each level. The document concludes with credits and information about the author.