Sonoma puts the last nail in the coffin for PostScript on macOS

Apple is clear about the removal in its release notes for Sonoma, saying that "macOS has removed the functionality for converting PostScript and EPS files to PDF format."

"As a result, CoreGraphics' CGPSConverter returns an error when invoked, ImageIO no longer converts EPS files, NSEPSImageRep does not display EPS files, and PMPrinterPrintWithFile does not accept a PostScript file for non-PostScript print queues," it elaborates.

It's a bit of a sad footnote for a one-time revolutionary technology that helped kick off the desktop publishing revolution in which Apple and Adobe were both such central players. But times have changed: In 2021, PostScript's inventor Charles Geschke passed away at age 81.

Dr John Warnock, who co-founded Adobe with Geschke, passed away in August, 2023 at age 82.

For the most part, Adobe's own PDF document format has succeeded PostScript, so this issue is unlikely to affect most people beyond those with archives of PostScript or EPS files.

PostScript's demise on the Mac shouldn't come as a shock to anyone who's been paying attention. The writing has been on the wall for years, as Apple has slowly dismantled support for PostScript in successive macOS releases.

This process began with Catalina's release in 2019, when Apple retired support for PostScript Type 1 fonts in favor of OpenType. Adobe itself followed suit by eliminating Type 1 font support in Photoshop in 2021.

The removal accelerated with the release of macOS Monterey 12.3, when Apple pulled the ability for PostScript files to be viewed inline. And in macOS Ventura, the Preview application removed PostScript conversion support.

PostScript's removal from the Mac is good security, opined Mac developer Dr. Howard Oakley. Security researchers have uncovered several serious vulnerabilities in common PostScript interpreters, he said.

"PostScript is an old stack-based interpreted language designed at a time when code security had barely been conceived, and malicious software hardly existed," wrote Oakley in a recent blog post. "Among its attractive features is the fact that any PostScript object can be treated as data, or executed as part of a program, and can itself generate new objects that can in turn be executed.

"More recently, security researchers have drawn attention to the fact that it's a gift for anyone wishing to write and distribute malicious code," Oakley added. "As it's effectively an image format, embedding malware inside a PostScript file could enable that to be run without user interaction, as with some other graphics formats."

Oakley noted those with a need to access PS and EPS files on their Mac still have a few options, including Adobe's commercial Distiller app, Artifex's Ghostscript, or a Virtual Machine (VM) running macOS Monterey.