Tivoization is the practice of designing hardware that incorporates
software
Software is a set of computer programs and associated software documentation, documentation and data (computing), data. This is in contrast to Computer hardware, hardware, from which the system is built and which actually performs the work.
...
under the terms of a
copyleft
Copyleft is the legal technique of granting certain freedoms over copies of copyrighted works with the requirement that the same rights be preserved in derivative works. In this sense, ''freedoms'' refers to the use of the work for any purpose, ...
software license
A software license is a legal instrument (usually by way of contract law, with or without printed material) governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both sour ...
like the
GNU General Public License
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end user
In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ulti ...
(GNU GPL), but uses
hardware restrictions or
digital rights management
Digital rights management (DRM) is the management of legal access to digital content. Various tools or technological protection measures (TPM) such as access control technologies can restrict the use of proprietary hardware and copyrighted work ...
(DRM) to prevent users from running modified versions of the software on that hardware.
Richard Stallman
Richard Matthew Stallman (; born March 16, 1953), also known by his initials, rms, is an American free software movement activist and programmer. He campaigns for software to be distributed in such a manner that its users have the freedom to u ...
coined the term in reference to
TiVo's use of GNU GPL licensed software on the TiVo brand
digital video recorders (DVR), which actively blocks users from running modified software on its hardware by design. Stallman believes this practice denies users some of the freedom that the GNU GPL was designed to protect. The
Free Software Foundation
The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed under copyleft ("s ...
refers to tivoized hardware as "tyrant devices".
Overview
TiVo's software incorporates the
Linux kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...
and
GNU software, both of which are licensed under version 2 of the
GNU General Public License
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end user
In product development, an end user (sometimes end-user) is a person who ultimately uses or is intended to ulti ...
(GPLv2). GPLv2 requires distributors to make the corresponding
source code
In computing, source code, or simply code, is any collection of code, with or without comment (computer programming), comments, written using a human-readable programming language, usually as plain text. The source code of a Computer program, p ...
available to each person who receives the software. The goal of this requirement is to allow users of GPL-covered software to modify the software to better suit their purposes.
However, Stallman asserts that TiVo circumvented this goal by making their products run programs only if the program's
digital signature
A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created b ...
matches those authorized by the manufacturer of the TiVo. While TiVo has complied with the GPL v2 requirement to release the source code for others to modify, any modified software will not run on TiVo's hardware.
Linus Torvalds
Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and, historically, the lead developer of the Linux kernel, used by Linux distributions and other operating systems such as Android. He also ...
, the original author of the Linux kernel, supported the use of DRM in response. Other Linux developers, including
Alan Cox, have expressed divergent opinions.
Stallman and the Free Software Foundation attempted to respond to some of these concerns. They have stated that their goal is for GPLv3 to allow private digital signatures for security purposes, but to still prevent tivoization.
Response
In 2006, the
Free Software Foundation
The Free Software Foundation (FSF) is a 501(c)(3) non-profit organization founded by Richard Stallman on October 4, 1985, to support the free software movement, with the organization's preference for software being distributed under copyleft ("s ...
(FSF) decided to combat TiVo's technical system of blocking users from running modified software. The FSF subsequently developed a new version of the
GNU General Public License (Version 3) which was designed to include language which prohibited this activity.
The
Linux kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...
, which is included in the
operating system
An operating system (OS) is system software that manages computer hardware, software resources, and provides common daemon (computing), services for computer programs.
Time-sharing operating systems scheduler (computing), schedule tasks for ef ...
of TiVo-branded hardware, is distributed under the terms of the GPLv2. The FSF's goal is to ensure that all recipients of software licensed under the GPLv3 are not restricted by hardware constraints on the modification of distributed software.
This new license provision was acknowledged by TiVo in its April 2007
SEC filing
The SEC filing is a financial statement or other formal document submitted to the U.S. Securities and Exchange Commission (SEC). Public companies, certain insiders, and broker-dealers are required to make regular SEC filings. Investors and fin ...
: "we may be unable to incorporate future enhancements to the GNU/Linux operating system into our software, which could adversely affect our business". The
Linux kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...
has not been changed to use GPLv3 due to certain problems perceived by its maintainers.
GNU GPLv3
One of the goals of
GNU General Public License Version 3 is to prevent tivoization. According to
Eben Moglen, "the license should prohibit technical means of evasion of its rules, with the same clarity that it prohibits legal evasion of its rules."
The second draft of the GPLv3 attempted to clarify this. However, some Linux kernel developers were still concerned that this draft may still prohibit beneficial uses of digital signatures.
In the third and fourth discussion drafts of the GPLv3, released 28 March 2007 and 31 May 2007 respectively, the anti-tivoization clause was limited so as not to apply when the software is distributed to a business. Thus, medical devices and voting machines would not be covered. The final, official GPLv3 was published on 29 June 2007 with no major changes in respect to tivoization relative to the fourth draft.
Linus Torvalds
Linus Benedict Torvalds ( , ; born 28 December 1969) is a Finnish software engineer who is the creator and, historically, the lead developer of the Linux kernel, used by Linux distributions and other operating systems such as Android. He also ...
said he was "pretty pleased" with the new draft's stance on
DRM. However, he still does not support
relicensing Software relicensing is applied in open-source software development when software licenses of software modules are incompatible and are required to be compatible for a greater combined work. Licenses applied to software as copyrightable works, in s ...
the Linux kernel under GPLv3, stating that:
In any case, offering the Linux kernel under a different license would likely be infeasible because of its very large number of copyright holders. Unlike most GPL software, the kernel is licensed only under GPLv2 without the wording "or, at
your option, any later version", therefore the explicit agreement of all copyright holders would be required to license it under a new version.
Some other projects widely used in tivoized embedded systems, such as
BusyBox
BusyBox is a software suite that provides several Unix utilities in a single executable file. It runs in a variety of POSIX environments such as Linux, Android, and FreeBSD, although many of the tools it provides are designed to work with int ...
, have also declined to move to GPLv3.
The
Creative Commons license
A Creative Commons (CC) license is one of several public copyright licenses that enable the free distribution of an otherwise copyrighted "work".A "work" is any creative material made by a person. A painting, a graphic, a book, a song/lyric ...
s also have anti-DRM clauses.
See also
*
Vendor lock-in
In economics, vendor lock-in, also known as proprietary lock-in or customer lock-in, makes a customer dependent on a vendor for products, unable to use another vendor without substantial switching costs.
The use of open standards and alternativ ...
*
Defective by Design
References
Further reading
Free Software Foundation definition of "Tivoization"by The Linux Information Project (LINFO)
– by Shashank Sharma August 9, 2006, from
NewsforgeTiVo's GPL-required modificationsto the
Linux kernel
The Linux kernel is a free and open-source, monolithic, modular, multitasking, Unix-like operating system kernel. It was originally authored in 1991 by Linus Torvalds for his i386-based PC, and it was soon adopted as the kernel for the GNU ...
,
glibc, and other software
*Richard Stallman's explanations of "tivoisation":
Italy, March 2006Japan, November 2006**
Stallman and Bruce Perens debating about GPL and tivoization (on Wikimedia Commons)
*
Eben Moglen's explanations:
Spain, June 2006*Ciarán O'Riordan's explanations:
Japan, November 2006Tivoisation explained – implementation and harms(article)
* with a focus on Tivoization
{{FOSS
Free software culture and documents
Technology neologisms
TiVo