The memo was not a policy statement but instead a clarification and guidance on the use of open source software (OSS) within the agency. It was issued by David Wennergren, deputy CIO of the U.S. Department of Defense (DoD).

In terms of guidance, the memo said OSS meets the definition of "commercial computer software" and that executive agencies are required to include open source when evaluating software that meets their computing needs.

In addition, the memo lays out a list of open source positives, including broad peer-review that helps eliminate defects, modification rights that help speed changes when needed, a reduction in the reliance on proprietary vendors, a licensing model that facilitates quick provisioning, cost reduction in some cases, reduction in maintenance and ownership costs, and favorable characteristics for rapid prototyping and experimentation.

"I would consider this a milestone day" said John Scott, director of open source software and open integration for Mercury Federal Systems, a technology consultancy to the U.S. government. Scott helped draft some of the open source guidance contained in the memo, which took about 18 months to draft. "The [2003] policy study was OK to use, but this one goes a bit further in expanding on what open source is and why you would want to use it. But it is not just about usage, it is also about helping create [OSS] by submitting changes back out to the public."