Xpdf is a

free and open-source Free and open-source software (FOSS) is software available under a Software license, license that grants users the right to use, modify, and distribute the software modified or not to everyone free of charge. FOSS is an inclusive umbrella term ...

PDF Portable document format (PDF), standardized as ISO 32000, is a file format developed by Adobe Inc., Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, computer hardware, ...

viewer and toolkit based on the Qt framework. Versions prior to 4.00 were written for the

X Window System The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at ...

and Motif.

Functions

Xpdf runs on nearly any

Unix-like A Unix-like (sometimes referred to as UN*X, *nix or *NIX) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Uni ...

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

. Binaries are also available for

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

. Xpdf can decode LZW and read encrypted PDFs. The official version obeys the DRM restrictions of PDF files, which can prevent copying, printing, or converting some PDF files. There are patches that make Xpdf ignore these DRM restrictions; the

Debian Debian () is a free and open-source software, free and open source Linux distribution, developed by the Debian Project, which was established by Ian Murdock in August 1993. Debian is one of the oldest operating systems based on the Linux kerne ...

distribution, for example, has these patches in place by default. Xpdf includes several programs that don't need an X Window System, including some that extract images from PDF files or convert PDF to

PostScript PostScript (PS) is a page description language and dynamically typed, stack-based programming language. It is most commonly used in the electronic publishing and desktop publishing realm, but as a Turing complete programming language, it c ...

or text. These programs run on DOS, Windows,

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

and

Unix Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

. Xpdf is also used as a back-end for other PDF readers frontends such as KPDF and GPDF, and its engine, without the X11 display components, is used for PDF viewers including BePDF on BeOS, '!PDF' on

RISC OS RISC OS () is an operating system designed to run on ARM architecture, ARM computers. Originally designed in 1987 by Acorn Computers of England, it was made for use in its new line of ARM-based Acorn Archimedes, Archimedes personal computers an ...

, and PalmPDF on

Palm OS Palm OS (also known as Garnet OS) is a discontinued mobile operating system initially developed by Palm, Inc., for personal digital assistants (PDAs) in 1996. Palm OS was designed for ease of use with a touchscreen-based graphical user interface. ...

and on

Windows Mobile Windows Mobile is a discontinued mobile operating system developed by Microsoft for smartphones and personal digital assistants (PDA). Designed to be the portable equivalent of the Windows desktop OS in the emerging Mobile device, mobile/port ...

. Two versions exist for

AmigaOS AmigaOS is a family of proprietary native operating systems of the Amiga and AmigaOne personal computers. It was developed first by Commodore International and introduced with the launch of the first Amiga, the Amiga 1000, in 1985. Early versions ...

. Xpdf needs a limited version of an X11 engine called Cygnix on the host system.

AmigaOS 4 AmigaOS 4 (abbreviated as OS4 or AOS4) is a line of Amiga operating systems which runs on PowerPC microprocessors. It is mainly based on AmigaOS 3.1 source code developed by Commodore International, Commodore, and partially on version 3.9 develop ...

included AmiPDF, a PDF viewer based on 3.01 version of the Xpdf. However both Apdf and AmiPDF are native and need no X11.

xpdf-utils

The associated package "xpdf-utils" or "poppler-utils" contains tools such as pdftotext and pdfimages.

Exploit

A vulnerability in the Xpdf implementation of the JBIG2 file format, re-used in Apple's

iOS Ios, Io or Nio (, ; ; locally Nios, Νιός) is a Greek island in the Cyclades group in the Aegean Sea. Ios is a hilly island with cliffs down to the sea on most sides. It is situated halfway between Naxos and Santorini. It is about long an ...

phone operating software, was used by the Pegasus spyware to implement a zero-click attack on iPhones by constructing an emulated computer architecture inside a JBIG2 stream. Apple fixed this "

FORCEDENTRY FORCEDENTRY, also capitalized as ForcedEntry, is a security exploit allegedly developed by NSO Group to deploy their Pegasus spyware. It enables the " zero-click" exploit that is prevalent in iOS 13 and below, but also compromises recent safegu ...

" vulnerability in iOS 14.8 in September 2021.

Notes and references

Sources

External links