Code

What is a .epsf file?

A .epsf file is an Encapsulated PostScript File Format (version 1.2). This is a code, script or executable format. Confusingly, this extension has been used by 4 different formats over the years — they're all listed below.

This extension has been used by more than one format

4 different formats have claimed .epsf over the years, so two files with the same extension aren't necessarily the same kind of thing.

How to open a .epsf file

VS Code opens and highlights nearly every text-based code format.
Never run a script you didn't write or trust.

The registry records this extension against Encapsulated PostScript File Format, Encapsulated PostScript File Format, Encapsulated PostScript File Format and others, so software from that family is the most likely match.

How to convert a .epsf file

Text-based code needs no conversion — just save with a different extension if a tool insists.

MIME type

When a .epsf file travels over the web, servers label it with this MIME type:

application/postscript

What's a MIME type?

The technical record

For archivists, developers and the merely curious: these are the PRONOM registry entries for .epsf.