Microsoft will soon release a Windows 7 tool under the GPL, after admitting the product violated the terms of the popular open-source license.

On Friday, the company said it will release the ImageMaster USB/DVD source code and binaries under GPLv2 next, following an internal investigation into the matter that found it had indeed violated the license.

The free tool was available for download through te Microsoft Store for customers to create bootable USB drives or DVD backup media from the electronic software edition of Windows 7.

ImageMaster had violated the GPL because it contained modified code that had been distributed without the corresponding source-code and because Microsoft had bolted on its own, restricted licensing terms.

Microsoft called the violation a mistake, and while the code had been supplied by a third party, it took responsibility for not having caught the violation during its own code review process.

The company said it has conducted a review of other code on the Microsoft Store site and found this was the only such incident. Further, Microsoft promised, it's taking measures to "apply what we have learned from this experience for future code reviews we perform."

Ironically, licensing specialist Black Duck this week reported 22 per cent of the average software product or application - or 700MB of code - contains open-source code. Black Duck surveyed 175 customers. The chances of running into GPLv2 are also high: Black Duck earlier this year reported GPLv2 accounts for 50.06 per cent of open source projects.

Company chief executive and president Tim Yeaton said in a statement organizations are using to open source to gain what he called significant competitive advantage in a "multi-source" development process. "The 'not invented here' mentality is rapidly disappearing," he said.

It seems Microsoft was unaware of this changing reality and the implications on its relationship with those outside the company building code for is products. ®