Matusow will be replaced at the helm of the Shared Source program by Bill Hilf, who is director of Platform Technology Strategy at Microsoft.
Hilf runs the infamous Linux Lab at Microsoft.
He will assume responsibilities as the spokesperson for the Shared Source Initiative as well as continue to carry on his other activities as head of platform technology strategy.
"Im pleased with the work done over the past five years by a community of hundreds within Microsoft," Matusow wrote in his blog Friday.
"Ive been just one piece of that larger puzzle, and now it is time for me to take on a new set of challenges. As of this week Im taking on a new role as a Director in the Corporate Standards Strategy Team. Ill be looking at the issues surrounding standards from strategy, policy, and communications points of view."
Matusow helped launch Microsoft Shared Source nearly five years ago, he said.
Since its inception the initiative has grown to include more than 80 programs for sharing Windows, .Net, and Office source code.
The program has attracted more than 2 million developers, the company said.
Meanwhile, Microsoft recently streamlined its licensing process, introducing the three new template licenses for Shared Source and paving the way for new programs to be rolled out smoothly, the company said.
"We are getting close to a hundred source code releases and have succeeded in delivering source code to more than two million developers worldwide," Matusow said in his blog.
"Beyond that, Shared Source will expand at an increasing rate. Product teams are broadly evaluating how we can engage development communities more effectively through source licensing.
"With the release of the Microsoft source code licenses in October, we made it easier for our product teams to share more code. Also, the simplicity and predictability of the licenses for the development community will make it yet more attractive for our teams to engage."