FORTUNE — Oracle’s cloud is almost seven years in the making—about the same amount of time it took for Larry Ellison to join Twitter. The outspoken CEO issued his first Tweet on Wednesday and, true to form, he used up much of his 140 characters to knock rival SAP: “Oracle’s got 100+ enterprise applications live in the #cloudtoday, SAP’s got nothin’ but SuccessFactors until 2020.”
As of Wednesday evening, Ellison had nearly 22,000 followers (and just one Tweet). But there was plenty more trash talking as he officially unveiled Oracle’s (ORCL) cloud strategy earlier in the day. Ellison didn’t just slam SAP (SAP), he also went after younger cloud companies like Salesforce (CRM) and Workday. In a release, he called the Oracle Cloud the “most comprehensive cloud on the planet Earth” and said other cloud vendors “only have niche assets.” Salesforce CEO Marc Benioff, who has 34,550 followers on Twitter, responded to Ellison’s claims with his own jab: “Beware of the false Tweet” (Benioff had previously referred to Oracle’s cloud as the “false cloud”).
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Meanwhile, SAP issued a statement in response to Ellison:
“As usual, you can tell who Oracle is most worried about by the competitors they criticize most. In this case, Larry’s crystal ball is cloudy. Building a profitable cloud business depends on scale—with 17 million users, SAP’s SuccessFactors business has the largest user base of any cloud apps provider.”
Oracle’s new cloud is large—the company says it will include about 100 applications, from core enterprise resource planning apps to human capital management, the kind of software used by HR departments. The Oracle Cloud will also offer platform services and social monitoring tools, among other products.
Of course size (and snarky Tweets) can only go so far. SAP and Oracle have taken different approaches, but both enterprise tech giants have spent billions of dollars bulking up their cloud offerings with a slew of recent acquisitions. And yet, they still make the majority of their revenue from sales of on-premise, not cloud-based, software, and have yet to prove they can transform themselves into major cloud computing players.
In Oracle’s case, it’s taken a bold bet by rewriting much of its software for the cloud. Then again, getting customers up and running on the new suite of products will likely be costly and time-consuming. One thing’s for sure: Assuming Ellison keeps Tweeting, the Twittersphere just got a whole lot more interesting.