PubKeep picks up where Microsoft Publisher signs off

Microsoft ended support for Publisher this month, but users with orphaned documents still have options.

Support for perpetual versions ended on October 13, but those copies will keep working without further security updates, bug fixes, or technical support.

Publisher left Microsoft 365 subscriptions on October 1, although existing installations may remain accessible until removal updates arrive. Those start reaching Current Channel devices in mid-November and Monthly Enterprise Channel devices in early December.

Microsoft first let users know in 2024 that the venerable application would be scrapped, and the Windows behemoth offered little comfort to those who needed it. Microsoft suggested Word and PowerPoint as alternatives, but neither directly opens Publisher's .pub files.

The Document Foundation, the organization behind LibreOffice, was quick to point users toward LibreOffice Draw, which uses the libmspub library to import Publisher files and can save them in OpenDocument Format (ODF). Other alternatives aim to recreate more of the Publisher experience.

Adam Anderly, founder of Texas-based Saint Systems, created PubKeep to replace Microsoft's application. PubKeep is proprietary, with no plans to open source the code. But it doesn't require a subscription: a one-time payment of $99 buys the application.

The application runs on Windows or macOS, and a lightweight browser version is available. It looks a lot like Publisher, and can handle files from Publisher 2000 through 2021. Publisher 97 and 98 are also supported, but the files are sent to a conversion service (with the user's approval) to be converted to a newer format, so anybody worried about data leaving their local device should think carefully before opening those older files.

Anderly told The Register that the project began after users expressed alarm about losing access to decades of files because of Microsoft's plans. The first challenge was the file format itself.

He said: "Microsoft never published a spec for the .pub format. It did document some of the pieces Publisher is built on: the OLE compound file container, the document properties, and the Office Drawing records used for shapes and pictures. For everything else, we used libmspub, the Document Liberation Project's open source parser behind LibreOffice's Publisher import, as a reference.

"Our testing showed it had gaps, so we wrote our own engine in TypeScript. The same engine runs in the desktop app and in the browser. From there we built a test harness around Publisher itself. We assembled a corpus of real-world .pub files. An evaluation engine renders each file two ways, through Publisher's own PDF export and through our engine, and compares the output page by page, so every change we make is scored against Publisher."

He added: "For the parts no one had documented, we made small, controlled changes to documents in Publisher and studied how the saved files changed. A licensed perpetual copy of Publisher on a Windows machine is the reference."

Anderly emphasized: "We never decompiled or modified Publisher itself. Beyond Microsoft's published specs and libmspub, everything we learned came from the files and PDFs Publisher produces."

We took a copy for a spin and it opened every .pub file we tried, although that was hardly an exhaustive compatibility test. Anderly said the company would rapidly address problems reported by users.

Register readers will be unsurprised to know that Claude Code is involved, something that Anderly says makes responsive support possible, with agents reproducing problems and writing fixes. "Most issues are fixed the same day," said Anderly. "That leaves us time to answer every report and email personally."

Although the code is proprietary, Anderly told us: "The .pubk format we save to is open, so anything you make in PubKeep isn't locked in the way .pub files were." PubKeep describes .pubk as a documented ZIP-based format containing JSON and images. That makes its contents inspectable, although it doesn't guarantee another application can reproduce the layout.

For Publisher users seeking a familiar replacement, PubKeep offers another option. The $99 price includes a year of support.

What's more striking is how quickly a relatively small team built something that reproduces much of Publisher's functionality.

PubKeep is part of a broader reimplementation trend. Other projects are taking on applications that remain very much alive, including Word, Excel, and Photoshop. ®