Facebook at Work chief Julien Codorniou Facebook

Facebook's Slack competitor for businesses will be publicly available next month and charge per monthly active user, The Information reported on Tuesday.

The enterprise messaging platform, which is called Facebook at Work, has been in closed beta since last January.

Business Insider reported in May that Facebook at Work would be made commercially available by the end of this summer or in the fall.

Previous reports said Facebook planned to only charge for premium features, like integrations with third-party apps. But one company testing the service that Business Insider talked to in May said that companies would pay a per-user, per-month fee. They had been quoted a cost between $1 to $5 a user by Facebook.

Here are some pictures of the service, which we originally ran last May.