The Document Foundation (TDF), the organization behind LibreOffice, asserts that Microsoft’s Office file formats continue to tie users and organizations to the Microsoft ecosystem. In a new analysis, the foundation argues that the widespread use of DOCX, XLSX, and PPTX undermines the digital sovereignty of businesses and governments, despite their formal status as standards.
This criticism is part of a broader campaign by TDF. Earlier this year, the organization advocated for the use of the Open Document Format (ODF) as the standard within the European Euro-Office initiative. It also succeeded in persuading the European Commission to offer an open document format alongside an Excel file during a public consultation, according to Neowin.
According to TDF, the problem is not Microsoft Office itself, but the dependency that arises as soon as documents are saved in proprietary file formats. The choice of format ultimately determines who will be able to fully open, edit, and reproduce documents in the future.
Compatibility as a strategic advantage
According to TDF, Microsoft’s Office Open XML (OOXML) formats are not fully interoperable in practice. Other office suites can usually open documents, but do not support all implementation details and extensions. This results in differences in formatting, fonts, tables, and layout.
Furthermore, Microsoft can add its own extensions to OOXML or modify existing implementations without competing software being able to support them immediately. According to TDF, this creates a lasting disadvantage for alternative office suites.
According to the foundation, it is precisely this limited incompatibility that forms the basis of vendor lock-in. Organizations perceive alternative office software as less reliable, which means Microsoft Office remains the safe choice for collaboration with customers, suppliers, and government agencies. TDF refers to this as a form of “silent friction” that discourages switching.
Criticism of OOXML
TDF also questions the status of OOXML as an international standard. Although the format has been approved by ISO, the foundation calls the standardization process one of the most controversial in the organization’s history. According to the authors, the standard primarily describes the existing behavior of Microsoft Office, including historical features and product-specific implementations, rather than serving as a neutral exchange standard.
In addition, Microsoft Office uses OOXML Transitional by default, while the technically cleaner variant, OOXML Strict, is rarely used. As a result, TDF argues that actual interoperability remains limited.
Archiving risk
For individual users, inconsistent formatting mainly leads to frustration, but for organizations, the consequences can be more serious. TDF points to legal documents, medical forms, and government records whose correct display depends on a single vendor. This brings the discussion to the issue of long-term archiving as well.
According to the foundation, documents are still readable today because Microsoft supports the format. For archives that must be preserved for decades, however, there is a dependency on whether Microsoft will continue that support in the future.
TDF therefore advocates for the consistent use of the Open Document Format (ODF), combined with open fonts and policies in which open standards are the norm for official documents.