GitHub, a start-up whose products software developers use to store and collaborate on code, on Thursday said that its CEO, co-founder Chris Wanstrath, will step down.

Wanstrath will remain on the board to help find his replacement, then will then become executive chairman of the company, which has more than 20 million users and $200 million in annualized recurring revenue. News of the move was originally reported by Forbes.

"As GitHub approaches 700 employees, with more than $200M in ARR, accelerating growth, and more than 20 million registered users, I'm confident that this is the moment to find a new CEO to lead us into the next stage of growth," Wanstrath said in a statement.

(ARR refers to annual recurring revenue, which measures revenue on an annualized basis based on current contracts, and is frequently used as a metric by companies who charge subscriptions.)

This is actually the second time Wanstrath is leaving the top position of the San Francisco company, which competes with Atlassian and Microsoft.

Wanstrath had previously stepped down in 2012 and let cofounder Tom Preston-Werner take the lead. But in early 2014, Preston-Werner moved to the president position, opening the way for Wanstrath to become CEO. A few months later GitHub launched an investigation into sexual harassment claims involving Preston-Werner, and Preston-Werner left the company.

Under his current tenure as CEO, GitHub has brought the enterprise version of its software to the Amazon Web Services and Microsoft Azure clouds, and most recently the company introduced a Business service tier.

GitHub, which raised $250 million at a $2 billion valuation in 2015, is No. 22 on CNBC's 2017 Disruptor 50 list.

"What we've accomplished over the past 10 years at GitHub has been mind-blowing, and I can't wait to see what we can accomplish over the next decade," Wanstrath said.