Facebook wants to be known for more than jealousy-inducing vacation photos and reminders of friends' birthdays. The social network has been steadily growing its business communications tool Workplace with the goal of becoming a serious rival to Slack.  

Workplace enables coworkers to communicate with one another similarly to how the consumer version of Facebook connects friends. The service, which launched last October, is now used by 30,000 businesses, according to Recode. That's nearly twice as many as six months ago, though Facebook did not disclose how many of them pay for the service or the number of individual users.

Market leader Slack, Inc.'s 2015 company of the year, reportedly has 5 million daily active users and $150 million in annual revenue. The company received inquiries from Amazon earlier this year about a potential acquisition that would value it at $9 billion or more, Bloomberg reported in June.

The one-year anniversary of Workplace also comes with some upgrades to the service. Facebook is adding new features including a group video chat and a desktop chat app, which would eliminate the need to keep Facebook open in a browser.

Facebook isn't the only tech giant trying to reshape office communications. Last November, Microsoft launched its own chat-based service, called Teams. The company announced in September that 125,000 organizations in 181 markets use the product.