Ibm has picked slack to power its chat communications companywide for its more than 350,000 employees. Report reveals that IBM has been experimenting with Slack and is now rolling it out to all employees.

Ibm teams have started using the chat app as far back as 2014. This has grown over time. Slack CEO Stewart Butterfield says the app will work for the largest organizations in the world.

Ibm has been the company’s biggest customer for years according to Slack. The new rollout makes IBM Slack’s largest customer to date.

This is a significant increase from the 165,000 users that Slack last reported in 2019 after the launch of its enterprise grid service. It’s not clear whether IBM is using the paid version of slack for all of its employees or a mix of the free and paid options.

Microsoft has successfully chased and overtaken slack in the past year. Teams are used actively by 20 million people daily compared to Slack’s 12 million.

Slack has previously claimed it’s not worried about Microsoft’s reach with Office 365. It even mocked Microsoft last year, accusing it of ripping off its ads.