LibreOffice reopens the Microsoft Publisher files Microsoft abandoned on October 13
On October 13, 2026, Microsoft killed Publisher: Microsoft 365 subscribers can no longer open their PUB files, a proprietary format three decades old. LibreOffice and Scribus, through the reverse-engineered libmspub library, reopen those documents: migrate them to ODF now, while they are still readable.
October 13, 2026. Microsoft pulls the plug on Publisher: the app reaches end of support, and Microsoft 365 subscribers can no longer open their PUB files. October 14, 2026. The Document Foundation announces that LibreOffice and Scribus, through the libmspub library reverse-engineered by the Document Liberation Project, reopen those documents. Why it matters: millions of newsletters, leaflets and calendars produced over thirty years are now locked inside a format their own creator abandoned — and the escape route exists, provided you migrate now.
What Microsoft unplugged, and what it offers instead
The calendar was known, but the cut is still brutal. On October 1, 2026, Publisher stopped shipping in Microsoft 365 subscriptions; on October 13, 2026, the perpetual version lost support as well. The practical result is stark: a Microsoft 365 subscriber can no longer open their PUB files — not just edit them: open them.
Microsoft’s official guidance illustrates the trap. The company suggests converting PUB files to PDF for viewing and to DOCX for editing. Both are dead ends: PDF freezes the layout without allowing editing, and DOCX is not a page-layout tool — Word breaks the composition of complex documents during conversion. Either way, the user is asked to move from one proprietary format controlled by a vendor to… another proprietary format controlled by the same vendor.
Because PUB is not an open standard, no one but Microsoft holds its specification. That is exactly what The Document Foundation calls out: when the format is proprietary, access to your documents vanishes with the application that created them.
The escape route: reverse-engineering your way back to your documents
The free-software community answered in its own characteristic way. The Document Liberation Project reverse-engineered the PUB format and produced libmspub, a library that decodes Publisher files. LibreOffice and Scribus rely on it to import those documents.
In practice, three paths are open to you:
- LibreOffice Draw opens, views and edits PUB files directly. It is not a desktop-publishing application, but it suffices for small multi-page documents such as newsletters, or single-page documents of any size.
- Scribus, the open-source desktop-publishing program, also imports PUB for real layout work — without, however, resting on a standard document format.
- ODF (OpenDocument Format) is the destination to aim for: an ISO standard, independent of any vendor, in which LibreOffice can save the recovered document.
The difference is not cosmetic. A file saved as ODF is yours: you can open it with LibreOffice, OnlyOffice or Collabora Office, today or in ten years. A PUB file remains at the mercy of a product decision.
The lesson that goes beyond Publisher
Publisher is not the first Microsoft application to disappear, and it will not be the last. The question this raises for anyone who manages documents — a town hall, a school, a non-profit, an SMB — comes down to one line: who controls access to your documents?
The answer depends on the format. A proprietary format hands control to the vendor. A standard, open format like ODF returns it to the user. That distinction, which sounds abstract, has a very real cost here: entire libraries of association bulletins, parish programmes and municipal calendars, produced over decades, becoming inaccessible overnight.
The moment to act is now — while it is still possible to open the files. Waiting means letting the migration window close as the machines and licences capable of reading PUB disappear from the estate.
Migrating without losing anything
Migrating a stock of PUB files should be planned like an infrastructure project, not treated as an end-of-day chore.
- Inventory first. Locate the PUB files: they often sleep on network shares, in mailboxes or on old machines. A
findover the shared volumes is enough to locate them. - Test the import on a sample. Open a few representative files in LibreOffice Draw or Scribus to gauge conversion fidelity. Simple documents nearly always survive; complex layouts may need a manual touch-up.
- Save to ODF. Convert the stock to ODF — or to PDF/A for archival of documents that no longer need editing. Both formats are built to last, unlike PUB.
# Locate Publisher files on a network share
find /mnt/share -type f \( -iname "*.pub" \) -printThe trap to avoid is procrastination. Every day that passes, the pool of machines capable of reading PUB shrinks. There will be no second chance: once the application is pulled from the Microsoft ecosystem, migration rests entirely on the open-source tools — and those already exist, but they must be used while the files are still readable.
What this says about an organisation’s format strategy
This affair is a textbook case for any serious document policy. The question is not “which application will open this file next year,” but “which format will outlive its application.”
PUB lasted thirty years, then died with its application. ODF is an ISO/IEC 26300 standard maintained by an independent consortium; PDF/A is designed for long-term archival. When a public body or a non-profit picks a format for long-lived documents — registers, bulletins, publications — it is really choosing who will hold the keys in twenty years.
LibreOffice is not just this story’s convenient “rescuer”: it embodies the structural answer. A free suite that reads and writes open standards guarantees your documents remain yours, whatever happens to the software that produced them.
A wave of retirements, not an isolated case
Publisher does not arrive alone. It belongs to a wave of retirements Microsoft set in motion around October 2026: users of Office 2021 and Office LTSC 2021 are being pushed toward the exit too, and The Document Foundation names them explicitly. The pattern is identical every time — an application disappears, and its proprietary format is orphaned overnight.
What makes Publisher more acute is the nature of its files. Where a Word document survives a conversion to DOCX and then to ODF reasonably well, a PUB file carries layout — columns, guides, text wrap — that no other proprietary format reproduces faithfully. The loss is not just access to the text; the composition itself risks vanishing.
That is precisely why the Document Liberation Project’s reverse-engineering has value beyond nostalgia. Every proprietary format decoded — libmspub for Publisher, and the sibling libraries for older Office formats — is a collective insurance policy against the disappearance of an application. As long as the format is documented, even after the fact, your documents remain recoverable.
Verdict
If you hold PUB files, act now, not in six months: open them in LibreOffice Draw or Scribus, validate the conversion on a sample, then save the stock as ODF or PDF/A. If you set document policy for a public body, a school or an SMB, make ODF the default format for every long-lived document, and treat the proprietary format as a debt to refinance. The lesson of Publisher is unambiguous: a document whose format belongs to a vendor stops being your document the day the vendor decides it no longer exists.