The U.S. Department of Defense (DoD) has just released "Clarifying Guidance Regarding Open Source Software (OSS)", a new official memo about open source software (OSS). This 2009 memo is important for anyone who works with the DoD (including contractors) on software and systems that include software... and I suspect it will influence many other organizations as well. The new memo tries to eliminate "misconceptions and misinterpretations" that inhibit use of OSS, and clear the way for wider use and development of OSS.