At a San Francisco event hosted by new chief executive Satya Nadella, Microsoft officially announced Thursday that it is releasing its popular Office suite for the iPad.

It's an announcement that's been a long time coming. While Microsoft has steadily been moving Office to the cloud -- first with its Office 365 cloud-based subscription model, then with apps for its own smartphones and for Apple's iPhone -- the firm has been reticent to put its key moneymaker on competing devices. Microsoft aims to always release its software on its own products first, and it has kept a tight leash on Microsoft software that runs on other companies' operating systems.

Nadella said the iPad Office move is part of Microsoft's new era of innovation, which will focus on bringing PC-level computing to all devices, no matter who makes them.

More than 1 billion people use Office across the world, and many of them are increasingly looking to access their documents and software on mobile devices. Microsoft is late to this game -- as it has hemmed and hawed about putting its popular suite on competing devices, others have stepped up to fill that gap. Apple's iWork, Google's Drive apps and other programs such as QuickOffice offer word-processing, spreadsheets and other applications on tablets and phones of all stripes.

Apps for Word, Excel and PowerPoint were available starting at 2 p.m. ET for the iPad in Apple's App Store. The apps have a touch-based interface that mirrors their PC versions, letting users do fairly sophisticated layout and text editing on their tablets just as they would on the PC.

These apps are free to download, and users will be able to read, view and present documents for free. To edit documents or create new documents from the iPad, users will need an Office 365 subscription, according to the company's official blog post.

The apps have the same collaborative features as the firm's cloud-based Office offerings and integrate with its cloud-storage app, OneDrive, to keep track of changes when multiple users weigh in on a single document. The PowerPoint app also has a presentation mode complete with a digital laser pointer -- something unique to the Office for iPad app that is triggered by holding one's finger on the screen.

Microsoft also announced a program called "In-Tune" for information technology professionals to manage devices, including those that run Google's Android mobile operating system or Apple's iOS.

The event also marked Nadella's first public appearance as Microsoft's chief executive since replacing longtime CEO Steve Ballmer in February. Nadella was on familiar ground Thursday, having come up through Microsoft's ranks via the Cloud and Enterprise team, which he led before becoming CEO. While not nearly the showman and salesman that Ballmer was, Nadella seemed at ease at the event and acknowledged how new he is to his position.

"It's Day 52 for me," he told members of the media at the event, which was livestreamed on the company's Web site. "Who's counting?"

Nadella said that Microsoft  was going to be focusing more on "ubiquitous computing" and noted that trends in technology have made gadgets less important than the software that powers them -- in other words, that it doesn't really  matter what kind of hardware is running Microsoft software, as long as it's running Microsoft software.

What motivates Microsoft, Nadella said, is to be where its customers are. There is "no tradeoff" to that, he said. "It's reality."

Microsoft shares, which had jumped last week on rumors that the firm was preparing a version of Office for the iPad, were down slightly after the announcement, at $39.64 per share.