Atlassian launched Stride last September as a way to better compete with Slack and the company said that while it had made progress with Stride, the partnership with Slack turned out to be a better option in the end. "We're very proud of what the team has built," Atlassian co-CEO Mike Cannon-Brookes told Bloomberg. "But at the same time, it is a crowded space, and there's a pragmatic option there."

Through its partnership with Atlassian, Slack says it will add new functionality to the integrations that currently exist between its product and Atlassian's Jira, Trello and Bitbucket products as well as introduce new integrations with additional Atlassian products, such as Confluence. "This partnership is about a joint vision of simplifying and automating the huge amount of effort that teams everywhere expend to stay aligned, coordinated and productive," Slack said in an announcement.

Rival Microsoft introduced its chat app Teams in 2016, and Slack took out a full-page ad in the New York Times welcoming the company to the space when it did. Earlier this month, Microsoft unveiled a free version of Teams, which offers a stronger set of features than the free version of Slack and gives those without an Office 365 account a chance to use the chat service.

HipChat and Stride users can sign up for Slack now and Atlassian has laid out a data migration process for its customers. Stride and HipChat products will be discontinued on February 15th, 2019. Existing HipChat Data Center and HipChat Server customers will have support until the end of their license period.

Update 7/26/18 6:01PM ET: This article has been updated to reflect that Slack has purchased the IP for HipChat and Stride, not the products themselves. Slack will not take on support for the products before they're discontinued and Atlassian will provide a migration path for HipChat and Stride customers that choose to switch to Slack.