That's because, as the de-facto standard used by businesses, educational establishments and government departments around the world, Office is a product that's exceptionally hard to compete against. In fact, history is littered with examples of productivity suites that no longer exist, blown out of the water by the Microsoft Office dreadnought.
Yet LibreOffice, sponsored by a nonprofit organization called The Document Foundation, aims to attract users with a free, open source alternative to Office with many of the features of Microsoft's offering. The project has been around for more than four years, and is a fork of OpenOffice.org, an open-sourced version of StarOffice which was originally released by Sun in 2000.
Michael Meeks, a leading LibreOffice developer, says the open source suite is currently being used by about 20 million Linux users. (LibreOffice is included in many Linux distributions.) He adds that update requests are also regularly received from 120 million different IP addresses with one million new ones appearing every week -- and suggests that in total there may be 80 million LibreOffice users around the globe.
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Those numbers may seem high for an open source productivity suite project, but even if they're correct they are dwarfed by the number of Office users: In February 2015 Microsoft estimated that its productivity suite is used by 1.2 billion people, and the Office for iPad and iPhone apps alone have been downloaded more than 80 million times.
LibreOffice must still work and play well with Microsoft Office
One of the key requirements for any software suite that aims to challenge Microsoft Office's dominance is that it allows users to open, edit and save documents in Office formats so that they can work alongside the majority of the rest of the world that still uses Office. (Office supports the international standard Open Document Format (ODF) as well as its own Office formats, but Meeks says its support for ODF is "woeful," and some Office features are not compatible with the open formats.)
In fact, LibreOffice users have found that the software is not always able to present Microsoft-formatted documents identically to the way that they would be formatted if they had been created natively in the appropriate Office application, but Meeks suggests that this is not a frequent problem. He also dismisses the idea that Office users may have a problem opening files created in LibreOffice and saved in a Microsoft format.
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"If a customer has a problem opening your files (created in LibreOffice) then they can always download a free copy of LibreOffice," he says. But while this is true in theory, in practice it's probably more likely that a customer will expect you to get a copy of Office if you want to do business with them, rather than download some software they've probably never heard of themselves.
Meeks also works at Collabora a U.K.-based company that provides commercial support and maintenance for LibreOffice and he says the company uses LibreOffice software without any interoperability problems. "We run a multimillion dollar business using LibreOffice and we routinely exchange documents with lawyers and it works fine," he maintains.
Duplicate or innovate
Positioning LibreOffice as an alternative to Office means that LibreOffice developers' hands are tied to a certain extent when it comes to choosing features and functionality to include, Meeks admits. That's because LibreOffice has no option but to reproduce many of Office's features to ensure compatibility. "Office creates files that we have to render, so that dictates some feature sets that we have to provide of course," he says.
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But he says that there is still plenty of scope for the open source project to take the lead. "The Office suite has been dead in terms of innovation, and that means that we have the opportunity to start to develop new stuff."
For example "Open source projects led with open document formats and Microsoft followed," he says. "And we had an idea for presentations that could be led from a mobile phone. We started that, and Microsoft copied us."
"Microsoft does great work, but we do, too," he adds. "Will we ever have a massive feature edge I am optimistic."
The problem for an open source project like LibreOffice is that Microsoft has huge resources that it can use to fund innovative new features. It can also catch up with competitors by copying any particularly appealing features introduced by the likes of LibreOffice.
Clippy, anyone
It also means that Microsoft can afford to fund the research and development of parts of its Office suite such as the user interface by hiring the top people in the field. That's something that open source project simply can't afford to do.
Meeks is not too worried by this. "One of the best beyond awesome design changes that Microsoft ever did was the introduction of Clippy. That was a disaster. I don't want to malign UI designers but having a big community of contributors is helpful because the changes that UI designers introduce don't always get universal acclaim. And look at Microsoft's ribbon interface: it had people screaming."
Meeks says that people prefer incremental changes to the user interface of a product they use every day, and this is something that the open source model does very well. "We iterate quickly, we are very agile and hopefully we make good progress."
Code quality is vital for a piece of software like LibreOffice, because users can easily abandon it for an alternative if it proves unreliable or prone to crashing. Research suggests that open source software tends to have a lower defect density (i.e. fewer bugs per thousand lines of code) than proprietary products, but to maintain downward pressure the Document Foundation organizes three-day community bug hunting sessions before releases. During these sessions mentors are available on IRC and by email to help less experienced volunteers triage bugs.
"We have made big progress on this front, and our Coverity score is in the range of bugs per million, fewer than most open source projects," says Meeks. (The average Coverity score for open source projects is 0.59 bugs per 1,000 lines of code, suggesting that LibreOffice is unusually bug-free.)
Watch out, Office 365
Perhaps the biggest problem for LibreOffice is that it may have missed the boat with its open source productivity software. That's because the focus for office software is shifting to the cloud: Microsoft is promoting Office 365, its cloud-based productivity suite, and it also offers a cut-down Microsoft Office Online for free. Other cloud-based alternatives include Google Docs, ThinkFree and Zoho.
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Recognizing that the cloud is likely to be an important battleground in the fight for users, Collabora and IceWarp a groupware developer based in Vermont have announced plans to jointly develop Web-based document editing technology and contribute these to the LibreOffice community. The idea is that this technology will then be used as the basis of a new service called LibreOffice Online.
"By the end of this year, our offering will be a replacement for Office 365," predicts Meeks. "Where there's an expectation that it should do XYZ we will have to follow that," he adds, implying that LibreOffice Online will closely resemble Office 365. The Document Foundation will host the service Meeks expects this to be lower cost than Office 365 and the server component will also be available free for companies to host themselves.
If and when LibreOffice Online actually appears is uncertain, although having some sort of cloud offering may be crucial if LibreOffice is to remain relevant. But even if LibreOffice Online is launched successfully, the question of whether the Document Foundation will have sufficient infrastructure to enable the online service to compete with the huge resources of Microsoft and Google in the cloud remains to be answered.