Xpdf is a

free and open-source Free and open-source software (FOSS) is a term used to refer to groups of software consisting of both free software and open-source software where anyone is freely licensed to use, copy, study, and change the software in any way, and the source ...

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

viewer for operating systems supported by the Qt toolkit. 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 provides the basic framework for a GUI environment: drawing and moving windows on the display device and interacting wit ...

and Motif.

Functions

Xpdf runs on nearly any

Unix-like A Unix-like (sometimes referred to as UN*X 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 Unix-li ...

operating system An operating system (OS) is system software that manages computer hardware, software resources, and provides common services for computer programs. Time-sharing operating systems schedule tasks for efficient use of the system and may also in ...

. Binaries are also available for

Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

. Xpdf can decode LZW and read encrypted PDFs. The official version obeys the

DRM DRM may refer to: Government, military and politics * Defense reform movement, U.S. campaign inspired by Col. John Boyd * Democratic Republic of Madagascar, a former socialist state (1975–1992) on Madagascar * Direction du renseignement milita ...

restrictions of PDF files, which can prevent copying, printing, or converting some PDF files. There are patches that make Xpdf ignore these DRM restrictions, and these restrictions are patched out by the

Debian Debian (), also known as Debian GNU/Linux, is a Linux distribution composed of free and open-source software, developed by the community-supported Debian Project, which was established by Ian Murdock on August 16, 1993. The first version of D ...

distribution. 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 in the electronic publishing and desktop publishing realm. It is a dynamically typed, concatenative programming language. It was created at Adobe Systems by John Warnock, Charles Geschke, Doug Br ...

or text. These programs run on

DOS DOS is shorthand for the MS-DOS and IBM PC DOS family of operating systems. DOS may also refer to: Computing * Data over signalling (DoS), multiplexing data onto a signalling channel * Denial-of-service attack (DoS), an attack on a communicat ...

, Windows,

Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...

and

Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser 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, and ot ...

. Xpdf is also used as a back-end for other PDF readers frontends such as

KPDF The KDE Gear (also known as the KDE Applications Bundle or KDE Applications) is a set of applications and supporting libraries that are developed by the KDE community, primarily used on Linux-based operating systems but mostly multiplatform, and ...

and GPDF, and its engine, without the X11 display components, is used for PDF viewers including

BePDF BePDF is a free software PDF reader for Haiku (operating system), Haiku, BeOS, and magnussoft ZETA. It is based on Xpdf. It was added in Haiku R1 alpha 1 as its sole PDF reader. The source code for BePDF is available via GitHub after a migratio ...

BeOS BeOS is an operating system for personal computers first developed by Be Inc. in 1990. It was first written to run on BeBox hardware. BeOS was positioned as a multimedia platform that could be used by a substantial population of desktop users a ...

, '!PDF' on

RISC OS RISC OS is a computer operating system originally designed by Acorn Computers Ltd in Cambridge, England. First released in 1987, it was designed to run on the ARM chipset, which Acorn had designed concurrently for use in its new line of Archim ...

, on PalmPDF on

Palm OS Palm OS (also known as Garnet OS) was a 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. It is provi ...

and on Windows Mobile. 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 version ...

. Xpdf needs a limited version of an X11 engine called

Cygnix Cygwin ( ) is a POSIX-compatible programming and runtime environment that runs natively on Microsoft Windows. Under Cygwin, source code designed for Unix-like operating systems may be compiled with minimal modification and executed. The Cygwin in ...

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, and partially on version 3.9 developed by Haage & Partner. "T ...

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 pdftotext is an Open-source license, open-source command-line utility for converting PDF files to plain text files—i.e. extracting text data from PDF-encapsulated files. It is freely available and included by default with many Linux Linux d ...

and

pdfimages pdfimages is an open-source command-line utility for lossless extraction of images from PDF files, including JPEG2000 and JBIG2 format when used with option -all. It is freely available as part of poppler-utils and xpdf-utils, and included in many ...

Exploit

A vulnerability in the Xpdf implementation of the

JBIG2 JBIG2 is an image compression standard for bi-level images, developed by the Joint Bi-level Image Experts Group. It is suitable for both lossless and lossy compression. According to a press release from the Group, in its lossless mode JBIG2 ty ...

file format, re-used in Apple's

iOS iOS (formerly iPhone OS) is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that powers many of the company's mobile devices, including the iPhone; the term also includes ...

phone operating software, was used by the Pegasus spyware to implement a zero-click attack on iPhones by constructing an emulated

computer architecture In computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, t ...

inside a JBIG2 stream. Apple fixed this " FORCEDENTRY" vulnerability in iOS 14.8 in September 2021.

Notes and references

Sources

External links