Bill Gates said he’s stepping down from the board of Microsoft Corp., the company he founded in 1975 and grew into the largest software maker, to devote more time to philanthropy.

“Microsoft will always be an important part of my life’s work and I will continue to be engaged with Satya and the technical leadership to help shape the vision and achieve the company’s ambitious goals,” Gates wrote in a blog post Friday. “I feel more optimistic than ever about the progress the company is making and how it can continue to benefit the world.”