The add-on adds semantic search capabilities to Word and can be tailored to different domain-specific languages, or ontologies. Its source code is available to developers on Microsoft's CodePlex open-source project website through the OSI-approved Microsoft Public License.

"Looking at the developer stack from higher to lower levels of abstraction, the add-in will be useful in three key areas: the development of new ontologies, investigation of new author interaction paradigms, and integration into publishing and semantic workflows," Microsoft program manager Pablo Fernicola wrote in his blog.

In my opinion, open source will accelerate the development of ontologies for Word, which Microsoft may otherwise not have devoted resource toward. It's a win-win situation and another example of Microsoft's targeted use of open source to advance the goals of its product teams.

As an aside, this announcement might have gotten more traction if not for the hubbub of Microsoft's patent-licensing lawsuit against GPS navigation device maker TomTom and the revelation that it had secret patent licensees.

Nothing is wrong with vendors having patent license agreements with Microsoft, but if licensees have been charged per-unit royalties by Microsoft, or were asked to share a portion of their revenues, the company placed its licensees in violation of GPL. The lawsuit certainly has become the elephant in the room for Microsoft in its outreach to the open-source community, and it is something that I will be writing more about shortly.