BitKeeper

Last updated
BitKeeper
Original author(s) BitMover Inc.
Initial releaseMay 4, 2000;24 years ago (2000-05-04)
Final release
7.3.3 / December 29, 2018;5 years ago (2018-12-29) [1]
Repository
Written in C
Operating system AIX, FreeBSD, HP-UX, IRIX, Linux, Mac OS X, NetBSD, OpenBSD, Solaris, Windows
Type Distributed revision control
License 2016: Apache-2.0 [a]
2000: Proprietary [b]
Website www.bitkeeper.org   OOjs UI icon edit-ltr-progressive.svg

BitKeeper is a discontinued software tool for distributed revision control of computer source code. Originally developed as proprietary software by BitMover Inc., a privately held company based in Los Gatos, California, [2] it was released as open-source software under the Apache-2.0 license on 9 May 2016. [3] BitKeeper is no longer being developed. [4] [5]

Contents

History

BitKeeper was originally developed by BitMover Inc., a privately held company from Los Gatos, California owned by Larry McVoy, who had previously designed TeamWare. [6]

BitKeeper and the Linux kernel

BitKeeper was first mentioned as a solution to some of the growing pains that Linux was having in September 1998. [7] Early access betas were available in May 1999 [8] and on May 4, 2000, the first public release of BitKeeper was made available. [9] [10] BitMover used to provide access to the system for certain open-source or free-software projects, one of which was the source code of the Linux kernel. The license for the "community" version of BitKeeper had allowed for developers to use the tool at no cost for open source or free software projects, provided those developers did not participate in the development of a competing tool (such as Concurrent Versions System, GNU arch, Subversion or ClearCase) for the duration of their usage of BitKeeper plus one year.[ citation needed ] This restriction applied regardless of whether the competing tool was free or proprietary. This version of BitKeeper also required that certain meta-information about changes be stored on computer servers operated by BitMover, an addition that made it impossible for community version users to run projects of which BitMover was unaware.

The decision made in 2002 to use BitKeeper for Linux kernel development was a controversial one. Some, including GNU Project founder Richard Stallman, expressed concern about proprietary tools being used on a flagship free project. While project leader Linus Torvalds and other core developers adopted BitKeeper, several key developers (including Linux veteran Alan Cox) refused to do so, citing the BitMover license, and voicing concern that the project was ceding some control to a proprietary developer. To mitigate these concerns, BitMover added gateways which allowed limited interoperation between the Linux BitKeeper servers (maintained by BitMover) and developers using CVS and Subversion. Even after this addition, flamewars occasionally broke out on the Linux kernel mailing list, often involving key kernel developers and BitMover's CEO Larry McVoy, who was also a Linux contributor. [11] [ original research? ]

In April 2005, BitMover announced that it would stop providing a version of BitKeeper free of charge to the community, giving as the reason the efforts of Andrew Tridgell, a developer employed by OSDL on an unrelated project, to develop a client which would show the metadata (data about revisions, possibly including differences between versions) instead of only the most recent version. Being able to see metadata and compare past versions is one of the core features of all version-control systems, but was not available to anyone without a commercial BitKeeper license, significantly inconveniencing most Linux kernel developers. Although BitMover decided to provide free commercial BitKeeper licenses to some kernel developers, it refused to give or sell licenses to anyone employed by OSDL, including Linus Torvalds and Andrew Morton, placing OSDL developers in the same position as other kernel developers. The Git project was launched with the intent of becoming the Linux kernel's source code management software, and was eventually adopted by Linux developers.

End of support for the "Free Use" version of BitKeeper was officially July 1, 2005, and users were required to switch to the commercial version or change version control system by then. Commercial users were also required not to produce any competing tools: In October 2005, McVoy contacted a customer using commercially licensed BitKeeper, demanding that an employee of the customer stop contributing to the Mercurial project, a GPL source management tool. Bryan O'Sullivan, the employee, responded, "To avoid any possible perception of conflict, I have volunteered to Larry that as long as I continue to use the commercial version of BitKeeper, I will not contribute to the development of Mercurial." [12]

Move to open-source

During the release of version 7.2ce at May 9, 2016, BitKeeper announced that it is starting to move from proprietary to open-source license, [13] eventually releasing the software under the Apache License version 2.

See also

Notes

  1. Apache-2.0 since 2016-05-09.
  2. Proprietary from 2000 until 2016-05-09.

Related Research Articles

<span class="mw-page-title-main">Free software</span> Software licensed to be freely used, modified and distributed

Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, not price; all users are legally free to do what they want with their copies of a free software regardless of how much is paid to obtain the program. Computer programs are deemed "free" if they give end-users ultimate control over the software and, subsequently, over their devices.

The free software movement is a social movement with the goal of obtaining and guaranteeing certain freedoms for software users, namely the freedoms to run, study, modify, and share copies of software. Software which meets these requirements, The Four Essential Freedoms of Free Software, is termed free software.

<span class="mw-page-title-main">GNU</span> Free software collection

GNU is an extensive collection of free software, which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operating systems popularly known as Linux. Most of GNU is licensed under the GNU Project's own General Public License (GPL).

<span class="mw-page-title-main">Linus Torvalds</span> Creator and lead developer of the Linux kernel (born 1969)

Linus Benedict Torvalds is a Finnish and American software engineer who is the creator and lead developer of the Linux kernel. He also created the distributed version control system Git.

<i>Revolution OS</i> 2001 documentary film

Revolution OS is a 2001 documentary film that traces the twenty-year history of GNU, Linux, open source, and the free software movement.

<span class="mw-page-title-main">GNU Project</span> Free software project

The GNU Project is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and computing devices by collaboratively developing and publishing software that gives everyone the rights to freely run the software, copy and distribute it, study it, and modify it. GNU software grants these rights in its license.

<span class="mw-page-title-main">GNU/Linux naming controversy</span> Issues of what to call a system with the GNU toolchain and the Linux kernel

The GNU/Linux naming controversy is a controversy regarding whether computer operating systems that use GNU software and the Linux kernel should be referred to as "GNU/Linux" or "Linux" systems.

<span class="mw-page-title-main">Monotone (software)</span> Revision control software

Monotone is an open source software tool for distributed revision control. It tracks revisions to files, groups sets of revisions into changesets, and tracks history across renames. The focus of the project is on integrity over performance. Monotone is designed for distributed operation, and makes heavy use of cryptographic primitives to track file revisions and to authenticate user actions.

<span class="mw-page-title-main">Larry McVoy</span> American computer programmer

Larry McVoy is the CEO of BitMover, the company that makes BitKeeper, a version control system that was used from February 2002 to early 2005 to manage the source code of the Linux kernel.

<span class="mw-page-title-main">Git</span> Distributed version control software system

Git is a distributed version control system that tracks versions of files. It is often used to control source code by programmers who are developing software collaboratively.

<span class="mw-page-title-main">Mercurial</span> Distributed revision-control tool for software developers

Mercurial is a distributed revision control tool for software developers. It is supported on Microsoft Windows, Linux, and other Unix-like systems, such as FreeBSD and macOS.

Alternative terms for free software, such as open source, FOSS, and FLOSS, have been a controversial issue among free and open-source software users from the late 1990s onwards. These terms share almost identical licence criteria and development practices.

Tivoization is the practice of designing hardware that incorporates software under the terms of a copyleft software license like the GNU General Public License, but uses hardware restrictions or digital rights management (DRM) to prevent users from running modified versions of the software on that hardware. Richard Stallman of the Free Software Foundation (FSF) coined the term in reference to TiVo's use of GNU GPL licensed software on the TiVo brand digital video recorders (DVR), which actively block modified software by design. Stallman believes this practice denies users some of the freedom that the GNU GPL was designed to protect. The FSF refers to tivoized hardware as "proprietary tyrants".

<span class="mw-page-title-main">Linux</span> Family of Unix-like operating systems

Linux 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 (distro), which includes the kernel and supporting system software and libraries, many of which are provided by the GNU Project.

<span class="mw-page-title-main">History of free and open-source software</span>

The history of free and open-source software begins at the advent of computer software in the early half of the 20th century. In the 1950s and 1960s, computer operating software and compilers were delivered as a part of hardware purchases without separate fees. At the time, source code—the human-readable form of software—was generally distributed with the software, providing the ability to fix bugs or add new functions. Universities were early adopters of computing technology. Many of the modifications developed by universities were openly shared, in keeping with the academic principles of sharing knowledge, and organizations sprung up to facilitate sharing.

Opposition to software patents is widespread in the free software community. In response, various mechanisms have been tried to defuse the perceived problem.

License compatibility is a legal framework that allows for pieces of software with different software licenses to be distributed together. The need for such a framework arises because the different licenses can contain contradictory requirements, rendering it impossible to legally combine source code from separately-licensed software in order to create and publish a new program. Proprietary licenses are generally program-specific and incompatible; authors must negotiate to combine code. Copyleft licenses are commonly deliberately incompatible with proprietary licenses, in order to prevent copyleft software from being re-licensed under a proprietary license, turning it into proprietary software. Many copyleft licenses explicitly allow relicensing under some other copyleft licenses. Permissive licenses are compatible with everything, including proprietary licenses; there is thus no guarantee that all derived works will remain under a permissive license.

Linux began in 1991 as a personal project by Finnish student Linus Torvalds to create a new free operating system kernel. The resulting Linux kernel has been marked by constant growth throughout its history. Since the initial release of its source code in 1991, it has grown from a small number of C files under a license prohibiting commercial distribution to the 4.15 version in 2018 with more than 23.3 million lines of source code, not counting comments, under the GNU General Public License v2 with a syscall exception meaning anything that uses the kernel via system calls are not subject to the GNU GPL.

<span class="mw-page-title-main">GNU General Public License</span> Series of free software licenses

The GNU General Public Licenses are a series of widely used free software licenses, or copyleft licenses, that guarantee end users the freedoms to run, study, share, and modify the software. The GPL was the first copyleft license for general use. It was originally written by Richard Stallman, the founder of the Free Software Foundation (FSF), for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. The licenses in the GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely-used permissive software licenses such as BSD, MIT, and Apache.

References

  1. "BitKeeper version 7.3.3 released Dec 29 2018". 9 February 2019.
  2. "Company information". BitMover. Archived from the original on 2016-08-01. Retrieved 2016-07-13.
  3. "BitKeeper". Archived from the original on 2016-05-10. Retrieved 2016-05-10.
  4. "BitKeeper community forum". BitMover. 31 December 2019. Retrieved 2020-05-06.
  5. "Contributors to bitkeeper". GitHub. Retrieved 2021-04-30.
  6. "Company information". BitMover. Archived from the original on 2016-08-01. Retrieved 2016-07-13.
  7. McVoy, Larry (30 Sep 1998). "A solution for growing pains". linux-kernel (Mailing list).
  8. "Current status". BitMover. 1999. Archived from the original on 1999-05-08.
  9. "Current status". BitMover. 4 May 2000. Archived from the original on 2000-06-17.
  10. "Development projects". LWN.net. 11 May 2000.
  11. Stallman, Richard (13 October 2002). "Bitkeeper outragem, old and new". linux-kernel (Mailing list). Retrieved 23 August 2019 via MARC.
  12. O'Sullivan, Bryan (30 September 2005). "Why I am no longer working on Mercurial". mercurial-devel (Mailing list). Archived from the original on 29 September 2007. Retrieved 14 April 2007.
  13. "BitKeeper announces opensource license ahead". BitKeeper.org. 9 May 2016.