Twitter Co-founder Evan Williams to quit its board after 12 years

Twitter on Friday announced that Co-founder Evan Williams will leave the social media company's board of directors at the end of the month after 12 years. Williams was the second-largest Twitter shareholder on the board behind Twitter CEO and Co-founder Jack Dorsey. Williams served as Twitter CEO from 2008 to 2010 and is now the CEO of publishing site 'Medium.com'.