LibreOffice blasts 'fake open source' OnlyOffice for working with Microsoft to lock users in

The Document Foundation (TDF) has been throwing some absolute daggers at Microsoft lately. It has actively been accusing the Windows maker of using absurdly complex XML schemas to trap users and even urged customers to abandon Windows 10 for Linux last year.

Now, it has shifted its crosshairs to a supposed ally, OnlyOffice, explicitly labeling the rival productivity suite as "fake open-source." According to TDF, OnlyOffice partners with Microsoft to enforce vendor lock-in by defaulting to Microsoft file formats instead of championing open standards.

TDF believes we are currently watching a brutal replay of the old browser wars mapped directly onto document formats. Back in the Internet Explorer 6 era, Microsoft tried to force the web into a proprietary shape. The World Wide Web Consortium (W3C) told Microsoft to kick rocks, refusing to validate its proposed changes because Internet Explorer failed to display sites correctly. That defiance apparently saved HTML.

Sadly, according to the foundation, the ISO dropped the ball when dealing with Microsoft Office Open XML (OOXML). The ISO blindly recognized OOXML as a standard when the format never actually functioned as one. Now, users have to tolerate endless formatting errors if someone tries to read a DOCX, XLSX, or PPTX file outside of Microsoft software.

TDF insists that proprietary file wrappers act like a digital pair of handcuffs protecting a $30 billion business:

Using a proprietary format for documents also has other drawbacks for users. In this way, they entrust the keys to their own content to someone they do not know, whose interests differ from their own.

In the best case scenario, the content is shared, and in the worst case scenario, it is at risk, as the Chief Prosecutor of the International Court of Justice unfortunately learned when Microsoft closed his email account on the orders of the President of the United States.

For its part, OnlyOffice promotes its high compatibility with Microsoft Office formats as a key feature. The company offers both a community edition under an open-source license and a proprietary enterprise version, a hybrid model that is not uncommon but sometimes draws scrutiny from open-source purists.