The Fastest-Growing Enterprise App Is Going After Microsoft Office, Google Docs, And Box

The business communication app Slack acquired document collaboration startup Spaces on Friday, making further inroads into the increasingly competitive work collaboration space.

This is Slack's first acquisition since its official launch in February. The financial terms of the deal were not disclosed.

Spaces makes a software for remote document editing and collaboration. Its features include real-time group editing and commenting, as well as file sharing and search. It's a two-person company founded by Simon Vallee, who sold his other startup Open Cal to Groupon, and Hans Larsen, an ex-Googler who used to work on the Google+ and Chrome teams.

It's unclear how exactly Slack plans to integrate Spaces into its current product - the new product will be released "in the coming months" - but Slack explained on its blog Friday that Spaces will help create a "new kind of document that's much better suited to how we work today."

"While a Space is a fine place to create a conventional written document (The Memo, The Proposal, and so on) it is designed with a deep recognition of the fact that we often use documents as containers for all kinds of other objects, like images, files, links, task lists and more," the post said.

Today's acquisition makes it obvious that Slack sees a huge opportunity in the document collaboration space, where Microsoft Office 365 and Google Docs are currently dominating.

Google, in fact, made huge updates last month to its Docs, Slides, and Sheets to make it available across all iOS and Android devices. In July, Box announced that its users would be able to open, edit, and share any file from Box within Microsoft Office products. Even Amazon revealed a similar document-editing product called Zocalo in July. Other small players, like Quip, are also making serious noise in this space.

Slack is a workplace collaboration app where users can chat, share files, and search across third-party apps like Dropbox, Google Drive and Twitter. It was founded by Flickr cofounder Stewart Butterfield, and is now considered one of the most viral enterprise apps ever, having grown almost 10x in just six months. It has over 200,000 daily active users and 60,000 paid customers, including Airbnb, eBay, AOL, and Adobe.

Its raised $60 million so far, from investors such as Andreessen Horowitz and Accel Partners, and is valued at more than $500 million.