The Linux Standard Base (LSB) was a joint project by several
Linux distribution
A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel functionality. Although the name does not imply product distribution per se, a distro—if distributed on its own—is oft ...
s under the organizational structure of the
Linux Foundation
The Linux Foundation (LF) is a non-profit organization established in 2000 to support Linux development and open-source software projects.
Background
The Linux Foundation started as Open Source Development Labs in 2000 to standardize and prom ...
to standardize the software system structure, including the
Filesystem Hierarchy Standard
The Filesystem Hierarchy Standard (FHS) is a reference describing the conventions used for the layout of Unix-like systems. It has been made popular by its use in Linux distributions, but it is used by other Unix-like systems as well. It is main ...
. LSB was based on the
POSIX
The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with comm ...
specification, the
Single UNIX Specification
The Single UNIX Specification (SUS) is a standard for computer operating systems, compliance with which is required to qualify for using the "UNIX" trademark. The standard specifies programming interfaces for the C language, a command-line shell, ...
(SUS), and several other open standards, but extended them in certain areas.
According to LSB:
The goal of the LSB is to develop and promote a set of open standards that will increase compatibility among Linux distributions and enable software applications to run on any compliant system even in binary form. In addition, the LSB will help coordinate efforts to recruit software vendors to port and write products for Linux Operating Systems.
LSB compliance might be certified for a product by a certification procedure.
LSB specified standard
libraries
A library is a collection of Book, books, and possibly other Document, materials and Media (communication), media, that is accessible for use by its members and members of allied institutions. Libraries provide physical (hard copies) or electron ...
(centered around the ), a number of commands and utilities that extend the
POSIX
The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with comm ...
standard, the layout of the
file system hierarchy,
run levels, the printing system, including
spoolers such as
CUPS and tools like
Foomatic, and several extensions to 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 ...
. It also specified boot facilities, such as ''$local_fs'', ''$network'', which were used to indicate service dependencies in
System V
Unix System V (pronounced: "System Five") is one of the first commercial versions of the Unix operating system. It was originally developed by AT&T and first released in 1983. Four major versions of System V were released, numbered 1, 2, 3, an ...
-style initialization scripts. A machine readable comment block at the top of a script provided the information necessary to determine at which point of the initialization process the script should be invoked; it was called the LSB header.
The command
lsb_release -a
was available in many systems to get the LSB version details, or could be made available by installing an appropriate package, for example the
redhat-lsb
package in
Red-Hat-flavored distributions such as
Fedora, or the
lsb-release
package in Debian-based distributions.
The standard stopped being updated in 2015 and current Linux distributions do not adhere to or offer it; however, the
lsb_release
command is sometimes still available. On February 7, 2023, a former maintainer of the LSB wrote, "The LSB project is essentially abandoned."
Backward compatibility

LSB was designed to be binary-compatible and produced a stable
application binary interface
An application binary interface (ABI) is an interface exposed by software that is defined for in-process machine code access. Often, the exposing software is a library, and the consumer is a program.
An ABI is at a relatively low-level of a ...
(ABI) for
independent software vendor
An independent software vendor (ISV), also known as a software publisher, is an organization specializing in making and selling software, in contrast to computer hardware, designed for mass or niche markets. This is in contrast to in-house softwa ...
s.
To provide backward compatibility, the LSB adopted an interface deprecation policy to give application developers enough time to adapt in case an interface was removed from LSB. An interface that is to be removed would first be marked as deprecated in an LSB release; that interface would still be supported in that release and at least two subsequent LSB releases. This allowed the developer to rely on every interface in LSB for a known time and also to plan for changes.
LSB 5.0 was the first major release that broke
backward compatibility
In telecommunications and computing, backward compatibility (or backwards compatibility) is a property of an operating system, software, real-world product, or technology that allows for interoperability with an older legacy system, or with Input ...
with earlier versions, as it removed
Qt 3; applications dynamically linked with Qt 3 libraries were not guaranteed to run on all LSB 5.0-compliant distributions.
Version history
* 1.0: Initial release June 29, 2001.
* 1.1: Released January 22, 2002. Added hardware-specific specifications (
IA-32
IA-32 (short for "Intel Architecture, 32-bit", commonly called ''i386'') is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the i386, 80386 microprocessor in 1985. IA-32 is the first incarn ...
).
* 1.2: Released June 28, 2002. Added hardware-specific specifications (
PowerPC
PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...
32-bit
In computer architecture, 32-bit computing refers to computer systems with a processor, memory, and other major system components that operate on data in a maximum of 32- bit units. Compared to smaller bit widths, 32-bit computers can perform la ...
). Certification began July 2002.
* 1.2.1: Released October 2002. Added
Itanium
Itanium (; ) is a discontinued family of 64-bit computing, 64-bit Intel microprocessors that implement the Intel Itanium architecture (formerly called IA-64). The Itanium architecture originated at Hewlett-Packard (HP), and was later jointly dev ...
.
* 1.3: Released December 17, 2002. Added hardware-specific specifications (Itanium, Enterprise System Architecture/390, z/Architecture).
* 2.0: Released August 31, 2004
** LSB is modularized to LSB-Core, LSB-CXX, LSB-Graphics, and LSB-
I18n (not released)
** New hardware-specific specifications (PowerPC
64-bit,
AMD64)
** Synchronized to
Single UNIX Specification
The Single UNIX Specification (SUS) is a standard for computer operating systems, compliance with which is required to qualify for using the "UNIX" trademark. The standard specifies programming interfaces for the C language, a command-line shell, ...
(SUS) version 3
* 2.0.1: Released October 21, 2004,
ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
version of LSB 2.0, which included specification for all hardware architectures (except LSB-Graphics, of which only a generic version is available).
* 2.1: Released March 11, 2005.
* 3.0: Released July 1, 2005. Among other library changes:
**
GNU C Library version 2.3.4
**
C++ ABI is changed to the one used by
gcc 3.4
** The core specification is updated to ISO
POSIX
The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with comm ...
(2003)
** Technical Corrigenda 1: 2005
* 3.1: Released October 31, 2005. This version has been submitted as ISO/IEC 23360:2006.
* 3.2: Released January 28, 2008. This version has been submitted as ISO/IEC 23360:2006.
* 4.0: Released November 11, 2008. This version contains the following features:
**
GNU C Library version 2.4
** Binary compatibility with LSB 3.x
** Easier to use
SDK
** Support for newer versions of
GTK
GTK (formerly GIMP ToolKit and GTK+) is a free software cross-platform widget toolkit for creating graphical user interfaces (GUIs). It is licensed under the terms of the GNU Lesser General Public License, allowing both Free software, free and ...
and
Cairo
Cairo ( ; , ) is the Capital city, capital and largest city of Egypt and the Cairo Governorate, being home to more than 10 million people. It is also part of the List of urban agglomerations in Africa, largest urban agglomeration in Africa, L ...
graphical libraries
**
Java
Java is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea (a part of Pacific Ocean) to the north. With a population of 156.9 million people (including Madura) in mid 2024, proje ...
(optional module)
** Simpler ways of creating LSB-compliant RPM packages
** Crypto API (via the
Network Security Services library) (optional module)
* 4.1: Released February 16, 2011:
** Java removed
** "Trial Use" modules from LSB 4.0, covering multimedia (
ALSA), security (NSS) and desktop miscellaneous (
xdg-utils) have been promoted as required submodules
** Updated
GTK+, Cairo and
CUPS libraries
** Three new test suites added
* 5.0: Released June 2, 2015, This version has been submitted as ISO/IEC 23360:2021
**
GNU C Library version 2.10 (for psiginfo)
** First major release that breaks backward compatibility with earlier versions (compatible with LSB 3.0, and mostly compatible with LSB 3.1 and later, with some exceptions)
** Incorporates the changes made in
FHS 3.0
** Qt 3 library has been removed
** Evolved module strategy; LSB is modularized to LSB Core, LSB Desktop, LSB Languages, LSB Imaging, and LSB Trial Use
ISO/IEC standard
The LSB, version 3.1, is registered as an official
ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
/
IEC international standard. The main parts of it are:
* ISO/IEC 23360-1:2006 Linux Standard Base (LSB) core specification 3.1 — Part 1: Generic specification
* ISO/IEC 23360-2:2006 Linux Standard Base (LSB) core specification 3.1 — Part 2: Specification for IA-32 architecture
* ISO/IEC 23360-3:2006 Linux Standard Base (LSB) core specification 3.1 — Part 3: Specification for IA-64 architecture
* ISO/IEC 23360-4:2006 Linux Standard Base (LSB) core specification 3.1 — Part 4: Specification for AMD64 architecture
* ISO/IEC 23360-5:2006 Linux Standard Base (LSB) core specification 3.1 — Part 5: Specification for
PPC32 architecture
* ISO/IEC 23360-6:2006 Linux Standard Base (LSB) core specification 3.1 — Part 6: Specification for
PPC64 architecture
* ISO/IEC 23360-7:2006 Linux Standard Base (LSB) core specification 3.1 — Part 7: Specification for
S390 architecture
* ISO/IEC 23360-8:2006 Linux Standard Base (LSB) core specification 3.1 — Part 8: Specification for
S390X architecture
There is also ISO/IEC TR 24715:2006 which identifies areas of conflict between ISO/IEC 23360 (the Linux Standard Base 3.1 specification) and the ISO/IEC 9945:2003 (POSIX) International Standard.
The LSB, version 5.0, is also registered as an official
ISO
The International Organization for Standardization (ISO ; ; ) is an independent, non-governmental, international standard development organization composed of representatives from the national standards organizations of member countries.
Me ...
/
IEC international standard.
*ISO/IEC 23360-1-1:2021 Linux Standard Base (LSB) — Part 1-1: Common definitions
*ISO/IEC 23360-1-2:2021 Linux Standard Base (LSB) — Part 1-2: Core specification generic part
*ISO/IEC 23360-1-3:2021 Linux Standard Base (LSB) — Part 1-3: Desktop specification generic part
*ISO/IEC 23360-1-4:2021 Linux Standard Base (LSB) — Part 1-4: Languages specification
*ISO/IEC 23360-1-5:2021 Linux Standard Base (LSB) — Part 1-5: Imaging specification
*ISO/IEC TS 23360-1-6:2021 Linux Standard Base (LSB) — Part 1-6: Graphics and Gtk3 specification
*ISO/IEC 23360-2-2:2021 Linux Standard Base (LSB) — Part 2-2: Core specification for X86-32 architecture
*ISO/IEC 23360-2-3:2021 Linux Standard Base (LSB) — Part 2-3: Desktop specification for X86-32 architecture
*ISO/IEC 23360-3-2:2021 Linux Standard Base (LSB) — Part 3-2: Core specification for IA64 (Itanium™) architecture
*ISO/IEC 23360-3-3:2021 Linux Standard Base (LSB) — Part 3-3: Desktop specification for IA64 (Itanium TM) architecture
*ISO/IEC 23360-4-2:2021 Linux Standard Base (LSB) — Part 4-2: Core specification for AMD64 (X86-64) architecture
*ISO/IEC 23360-4-3:2021 Linux Standard Base (LSB) — Part 4-3: Desktop specification for AMD64 (X86-64) architecture
*ISO/IEC 23360-5-2:2021 Linux Standard Base (LSB) — Part 5-2: Core specification for PowerPC 32 architecture
*ISO/IEC 23360-5-3:2021 Linux Standard Base (LSB) — Part 5-3: Desktop specification for PowerPC 32 architecture
*ISO/IEC 23360-6-2:2021 Linux Standard Base (LSB) — Part 6-2: Core specification for PowerPC 64 architecture
*ISO/IEC 23360-6-3:2021 Linux Standard Base (LSB) — Part 6-3: Desktop specification for PowerPC 64 architecture
*ISO/IEC 23360-7-2:2021 Linux Standard Base (LSB) — Part 7-2: Core specification for S390 architecture
*ISO/IEC 23360-7-3:2021 Linux Standard Base (LSB) — Part 7-3: Desktop specification for S390 architecture
*ISO/IEC 23360-8-2:2021 Linux Standard Base (LSB) — Part 8-2: Core specification for S390X architecture
*ISO/IEC 23360-8-3:2021 Linux Standard Base (LSB) — Part 8-3: Desktop specification for S390X architecture
ISO/IEC 23360 and ISO/IEC TR 24715 can be freely downloaded from ISO website.
Reception
While LSB was a standard and without a competitor, it was followed only by few
Linux distribution
A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel functionality. Although the name does not imply product distribution per se, a distro—if distributed on its own—is oft ...
s. For instance, only 21 distribution releases (versions) were certified for LSB version 4.0, notably
Red Flag Linux Desktop 6.0,
Red Hat Enterprise Linux
Red Hat Enterprise Linux (RHEL) is a commercial Linux distribution developed by Red Hat. Red Hat Enterprise Linux is released in server versions for x86-64, Power ISA, ARM64, and IBM Z and a desktop version for x86-64. Fedora Linux and ...
6.0,
SUSE Linux Enterprise 11, and
Ubuntu 9.04 (Jaunty Jackalope); even fewer were certified for version 4.1.
The LSB was criticized for not taking input from projects, most notably 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 ...
project, outside the sphere of its member companies.
Choice of the RPM package format
LSB specified that software packages should either be delivered as an LSB-compliant installer, or (preferably) be delivered in a restricted form of the
RPM Package Manager
RPM Package Manager (RPM) (originally Red Hat Package Manager, now a recursive acronym) is a free and open-source package management system. The name RPM refers to the file format and the package manager program itself. RPM was intended primar ...
format.
This choice of package format precluded the use of other existing package formats not compatible with RPM. To address this, the standard did not dictate which package format the system must use for its own packages, merely that RPM must be supported to allow packages from third-party distributors to be installed on a conforming system.
Limitations on Debian
Debian included optional support for LSB early on, at version 1.1 in "woody" (3.0; July 19, 2002), 2.0 in "sarge" (3.1; June 6, 2005), 3.1 in "etch" (4.0; April 8, 2007), 3.2 in "lenny" (5.0; February 14, 2009) and 4.1 in "wheezy" (7; May 4, 2013). To use foreign LSB-compliant RPM packages, the
end-user
In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ultimately use a product. The end user stands in contrast to users who support or maintain the product, such as sysops, system administrato ...
needs to use Debian's
Alien program to transform them into the native package format and then install them.
The LSB-specified RPM format had a restricted subset of RPM features—to block usage of RPM features that would be untranslatable to .deb with Alien or other package conversion programs, and vice versa, as each format has capabilities the other lacks. In practice, not all Linux binary packages were necessarily LSB-compliant, so while most could be converted between .rpm and .deb, this operation was restricted to a subset of packages.
By using Alien, Debian was LSB-compatible for all intents and purposes, but according to the description of their
lsb
package,
the presence of the package "does not imply that we believe that Debian fully complies with the Linux Standard Base, and should not be construed as a statement that Debian is LSB-compliant."
[
Debian strived to comply with the LSB, but with many limitations. However, this effort ceased around July 2015 due to lack of interest and workforce inside the project. In September 2015, the Debian project confirmed that while support for ]Filesystem Hierarchy Standard
The Filesystem Hierarchy Standard (FHS) is a reference describing the conventions used for the layout of Unix-like systems. It has been made popular by its use in Linux distributions, but it is used by other Unix-like systems as well. It is main ...
(FHS) would continue, support for LSB had been dropped. Ubuntu followed Debian in November 2015.
Quality of compliance test suites
Additionally, the compliance test suites were criticized for being buggy and incomplete—most notably, in 2005 Ulrich Drepper criticized the LSB for poorly written tests which can cause incompatibility between LSB-certified distributions when some implement incorrect behavior to make buggy tests work, while others apply for and receive waivers from complying with the tests. He also denounced a lack of application testing, pointing out that testing only distributions can never solve the problem of applications relying on implementation-defined behavior.[
For the vendors considering LSB certifications in their portability efforts, the ]Linux Foundation
The Linux Foundation (LF) is a non-profit organization established in 2000 to support Linux development and open-source software projects.
Background
The Linux Foundation started as Open Source Development Labs in 2000 to standardize and prom ...
sponsored a tool that analyzed and provided guidance on symbols and libraries that go beyond the LSB.
See also
* Intel Binary Compatibility Standard (iBCS)
* POSIX
The Portable Operating System Interface (POSIX; ) is a family of standards specified by the IEEE Computer Society for maintaining compatibility between operating systems. POSIX defines application programming interfaces (APIs), along with comm ...
(Portable Operating System Interface)
References
External links
Linux Standard Base Specifications Archive
linuxfoundation.org
Linux Standard Base (LSB)
wiki.linuxfoundation.org
Open Linux VERification (OLVER) Project
linuxtesting.org
search for lsb packages
pkgs.org
lsb
pkgs.org
lsb in Launchpad
launchpad.net - bug reports
Media:
Additional Vendors Participate in Growing LSB Effort
1998, debian.org - describes the breakdown of teams (at the time) and who was involved, of historical interest
Four Linux Vendors Agree On An LSB Implementation
2004, slashdot.org
Yes, the LSB Has Value
2005, licquia.org – response to Drepper by Jeff Licquia
{{Linux Foundation
Interfaces of the Linux kernel
ISO standards
Linux
Linux APIs
Linux Foundation