Salesforce’s nearly $28 billion Slack-quisition is shaking up the software world by pushing competitors to consider big bets of their own.

The jumbo-size deal for the workplace instant messaging service, announced Tuesday, can be viewed as a salvo directed at a common foe. Salesforce and Slack are most obviously taking on Microsoft, the Office juggernaut whose grip on virtual workplaces tightened this year as the number of people working remotely soared during the pandemic.

Slack was wounded by the surging use of Microsoft Teams, the company’s newly popular teleconferencing tool. Videoconferencing service Zoom added to Slack’s challenges.

But there’s more to the Slack-force combo than joining forces against Microsoft. Salesforce is also trying, preemptively, to keep ahead of rising rivals like Google. The search giant is keenly interested in growing its cloud computing division alongside its business collaboration tools, yet its many attempts at developing chat services—Allo, Duo, Hangouts—have floundered.

With Slack now off the table, analysts expect Salesforce’s rivals to make big bets too. As Daniel Ives, managing director at Wedbush Securities, writes in a research note, the Slack acquisition could “set off a chain reaction for more cloud software deals in 2021 despite the run-up in valuations over the past nine months.” In addition to Microsoft and Google, possible acquirers abound: Adobe, Amazon, Atlassian, Cisco, DocuSign, Dropbox, IBM, Oracle, SAP, ServiceNow, Twilio, Workday, and plenty of others.

Here are five cloud business toolmakers that may be ripe for the taking.

Airtable

Maker of a spreadsheet-cum-database, Airtable helps people stay on track with projects. The company was founded by Howie Liu in 2012, who briefly led “social CRM”—or social media–centric customer relationship management—at Salesforce after selling it his earlier company, Etacts. Liu, who raised $185 million in fresh funding for Airtable in September, tells TechCrunch he has no interest in an exit anytime soon. But then again, Salesforce CEO Marc Benioff said he had no interest in acquisitions just a few months before he made his biggest one ever.

Asana

Another online task manager for businesses, Asana was founded by former Facebookers—including Dustin Moskovitz, a Harvard dormmate of Mark Zuckerberg’s—at the end of 2008. The yoga pose–named company went public this fall on the same day as data-miner Palantir, using a direct listing (like trendsetter Slack). With a market capitalization of $4 billion, a purchase wouldn’t necessarily empty the wallet of a tech-giant suitor. And the appetite is apparently there: Adobe recently agreed to buy Asana rival Workfront for $1.5 billion.

Box

Box offers just that, a box—for electronic storage. The file-sharer helps people access documents and other digital content remotely. Bearing a market capitalization that’s one-third of its similarly named archrival, Dropbox, Box could be considered a budget buy. “This is Salesforce’s Instagram,” said Aaron Levie, Box’s chief executive, praising Benioff’s M&A of Slack with a favorable comparison to Facebook’s prescient photo-app purchase. Maybe Box could be someone’s WhatsApp?

Notarize

A purveyor of electronic signatures, Notarize specializes in—you guessed it—notarization. The startup, founded in 2015, helps deals get done digitally. E-signature star DocuSign bought adjacent startup Liveoak this summer, and Dropbox picked up a signature-themed company, HelloSign, last year. Notarize already partners with Adobe. As more contracts are consummated through computers, a Big Tech company could make the tie-up official and ink the dotted line.

Symphony

Like Slack, Symphony offers an instant messaging service, except it’s built first and foremost for bankers. Last privately valued at more than $1 billion, according to equity-tracker PitchBook, Symphony could be a handy add-on for a cloud company interested in wooing Wall Street. Perhaps Amazon-laggards like Oracle or IBM, known to talk up the so-called hybrid cloud (hosting computers part remote, part on-site), could make a match.