Meet the top 100 business visionaries creating value for the world

85. Stewart Butterfield

Founder and CEO, Slack

Two-year-old Slack, which aims to replace internal company emails with real-time chat channels, has seen remarkable growth, now boasting 2 million daily active users and a valuation approaching $4 billion. It has tamed the beast of email — companies using Slack report almost a 50% drop in internal email.

But Slack, founded and run by Stewart Butterfield, is also leading the way in diversity in an industry that's still largely dominated by white men. According to its September 2015 diversity report, more than 40% of Slack employees report to a woman as their manager, and 45% of the company's total employees are women. When the company won a TechCrunch award for fastest-rising startup of 2015, it sent four women employees to pick up the award instead of Butterfield.

Butterfield, who founded Flickr and sold it to Yahoo before starting Slack, also strives to break the usual startup mold of around-the-clock work, and instead he has instilled a motto of "work hard and go home."