Last September, the software company Atlassian launched a new workplace chat app called Stride, aimed squarely at taking on the similar app Slack. “We’ve been thrilled by the excitement we’ve seen from the tens of thousands of teams who have adopted it as their communication platform,” the company gushed in a March blog post.

Now, less than a year after the launch, Atlassian is pulling the plug on the product, along with its earlier workplace chat app HipChat. Atlassian said it will discontinue the two products by Feb. 15, 2019, and exit the communications business.

Slack surpassed HipChat in users in late 2014 and has outpaced HipChat ever since, according to Zapier, which offers tools that enable users to connect cloud-hosted applications. Zapier

To top it off, it is transferring the intellectual property for Stride and HipChat to Slack, as part of a deal the companies described as a “partnership.” Slack will migrate Atlassian’s users to its product. Atlassian also made an "equity investment" in Slack that Slack calls "small, but symbolically important." The companies didn't disclose the terms of the deal.

The deal seems confirms what millions of office workers already know: Slack has become the dominant tool for workplace messaging. The company boasts more active users than Microsoft’s competing Teams product, including many who are surprisingly passionate about it.

Slack started eating into HipChat’s market share in 2014, says Wade Foster, CEO of Zapier, which offers tools that enable users to connect different cloud-hosted applications. According to Zapier’s data, the number of people linking Slack to other applications passed the number of people doing the same with HipChat by the end of 2014. The number of people using HipChat with Zapier soon declined, while the number using Slack skyrocketed.

It's also an admission of defeat from Atlassian. “They gave up on a third-place product to focus on being first elsewhere with developers. Must have been a very hard choice,” says Ross Mayfield, the founder of Pingpad, a startup building a collaboration tool for Slack and other workplace chat platforms.

The deal still could have big upsides for Atlassian, says Jonathan Allan Kees, a senior analyst at Summit Insights Group. The two companies will cross-promote each other's products, which could bring Atlassian new customers for products including its bug-tracking application JIRA. "Communications is a very busy space in terms of peers, and this will allow Atlassian to focus on its core products, which are growing," Kees says. Indeed, investors pushed Atlassian's stock up 15% in after-hours trading, after the deal was announced.