KDE
From Wikipedia, the free encyclopedia
| K Desktop Environment | |
|---|---|
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 A screenshot of KDE 4, showing the default desktop with Dolphin, System Settings and the Kickoff menu.  A screenshot of KDE 3.5, showing the default logout prompt. |
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| Developed by | The KDE Team |
| Initial release | 1996 |
| Stable release | 4.0.4 (May 6, 2008) [+/−] |
| Preview release | 4.1 Beta1 (May 27, 2008) [+/−] |
| Written in | C++ and Qt |
| Platform | GNU/Linux and others |
| Available in | Multilingual (more than 80 different languages) |
| Development status | active |
| Genre | Desktop environment |
| License | GNU General Public License and others[1] |
| Website | www.kde.org |
KDE (K Desktop Environment) (IPA: /ˌkeɪdiːˈiː/) is a free software project which aims to be a powerful system for an easy-to-use desktop environment. The goal of the project is to provide basic desktop functions and applications for daily needs as well as tools and documentation for developers to write stand-alone applications for the system. In this regard, the KDE project serves as an umbrella project for many standalone applications and smaller projects that are based on KDE technology. These include KOffice, KDevelop, Amarok, K3b and many others.
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[edit] History
[edit] Origins
KDE was founded in 1996 by Matthias Ettrich, who was then a student at the Eberhard Karls University of Tübingen. At the time, he was troubled by certain aspects of the Unix desktop. Among his qualms was that none of the applications looked, felt, or worked alike. He proposed the formation of not only a set of applications, but rather a desktop environment, in which users could expect things to look, feel, and work consistently. He also wanted to make this desktop easy to use; one of his complaints with desktop applications of the time was that his girlfriend could not use them. His initial Usenet post spurred a lot of interest, and the KDE project was born.[2]
The name KDE was intended as a word play on the existing Common Desktop Environment, available for Unix systems. CDE was an X11-based user environment jointly developed by HP, IBM, and Sun, through the X/Open Company, with an interface and productivity tools based on the Motif graphical widget toolkit. It was supposed to be an intuitively easy-to-use desktop computer environment.[3] The K was originally suggested to stand for "Kool", but it was quickly decided that the K should stand for nothing in particular. Additionally, one of the tips in certain versions of KDE 3 incorrectly states that the K currently is just meant to be the letter before L in the Latin alphabet, the first letter in the word Linux (which is where KDE is usually run).[4]
Matthias Ettrich chose to use the Qt toolkit for the KDE project. Other programmers quickly started developing KDE/Qt applications, and by early 1997, a few applications were being released. At the time, Qt did not use a free software license and members of the GNU project became concerned about the use of such a toolkit for building a free software desktop and applications. Notably, KDE was removed from Debian because the project interpreted the GPL as not allowing KDE to be linked to Qt. Two projects were started: "Harmony", to create a Free replacement for the Qt libraries, and the GNOME project to create a new desktop without Qt and built entirely on top of free software.
[edit] First series
On 12 July 1998 KDE 1.0 was released. In the release announcement the KDE team outlined the project and its reasons for creation:
| “ | KDE is a network transparent, contemporary desktop environment for UNIX workstations. KDE seeks to fill the need for an easy to use desktop for Unix workstations, similar to the desktop environments found under the MacOS or Window95/NT. We believe that the UNIX operating system is the best operating system available today. In fact UNIX has been the undisputed choice of the information technology professional for many years. When it comes to stability, scalability and openness there is no competition to UNIX. However, the lack of an easy to use contemporary desktop environment for UNIX has prevented UNIX from finding its way onto the desktops of the typical computer user in offices and homes.
With KDE there is now an easy to use, contemporary desktop environment available for UNIX. Together with a free implementation of UNIX such as Linux, UNIX/KDE constitutes a completely free and open computing platform available to anyone free of charge including its source code for anyone to modify. While there will always be room for improvement we believe to have delivered a viable alternative to some of the more commonly found and commercial operating systems/desktops combinations available today. It is our hope that the combination UNIX/KDE will finally bring open, reliable, stable and monopoly free computing to the average computer. |
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— KDE 1.0 Release Announcement[5]
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In November 1998, the Qt toolkit was dual-licensed under the free/open source Q Public License (QPL) & commercial-licence (proprietary software is required to pay a licence fee to Trolltech) The same year, the KDE Free Qt foundation[6] was created which guarantees that Qt would fall under a variant of the very liberal BSD license should Trolltech cease to exist or no free/open source version of Qt be released during 12 months. Debate continued about compatibility with the GNU General Public License (GPL), so in September 2000, Trolltech made the Unix version of the Qt libraries available under the GPL, in addition to the QPL, which eliminated the concerns of the Free Software Foundation.
[edit] Second and third series
The second series of releases, KDE 2, introduced significant technological improvements.[7] These included DCOP (Desktop COmmunication Protocol), KIO, an application I/O library. KParts, a component object model, allowing an application to embed another within itself, and KHTML, a HTML rendering and drawing engine.[7]
The third series was much larger than the previous series, consisting of six major releases. The API changes between KDE 2 and KDE 3 were comparatively minor, meaning that the KDE 3 can be seen as largely a continuation of the KDE 2 series. All releases of KDE 3 are built upon Qt 3, which was only released under the GPL for Linux and Unix-like operating systems, including Mac OS X. For that reason, KDE 3 is only available on Windows through ports involving an X server.
[edit] Fourth series
KDE 4 is based on Qt 4 which is also released under the GPL for Windows and Mac OS X. Therefore KDE 4 applications can run natively on these operating systems as well.
KDE 4 includes many new technologies and technical changes. The centerpiece is a redesigned desktop and panels collectively called Plasma which integrates Kicker, KDesktop, and SuperKaramba and is intended to update the decades-old desktop metaphor. There are a number of new frameworks, including Phonon, a new multimedia interface making KDE independent of any one specific media backend, Solid, an API for network and portable devices, and Decibel, a new communication framework to integrate all communication protocols into the desktop. Also featured is a metadata and search framework, incorporating Strigi as a full-text file indexing service, and NEPOMUK with KDE integration.[8]
[edit] Organization
Like many free/open source software projects, KDE is primarily a volunteer effort, although various companies, such as Novell (in the form of SuSE), Trolltech, and Mandriva employ developers to work on the project. Since a large number of individuals contribute to KDE in various ways (e.g. code, translation, artwork), organization of such a project is complex. Most problems are discussed on a number of different mailing lists. Important decisions, such as release dates and inclusion of new applications, are made on the kde-core-devel list by the so-called core developers. These are developers who have made significant contributions to KDE over a long period of time. Decisions are not made by a formal voting process, but by discussion on the mailing lists. In most cases this seems to work well, and major debates (such as the question of whether the KDE 2 API should be broken in favour of KDE 3) are rare.
The KDE project and related events are frequently sponsored by individuals, universities, and businesses.[9] On 15 October 2006, it was announced that Mark Shuttleworth became the first patron of KDE, the highest level of sponsorship available.[10] On 2007-07-07, it was announced that Intel Corporation and Novell became patrons of KDE.[11]
While developers and users are now located all over the world, the project retains a strong base in Germany. The web servers are located at the universities of Tübingen and Kaiserslautern, a German non-profit organization (KDE e.V.) owns the trademark on "KDE" and KDE conferences often take place in Germany.
[edit] Identity
Many KDE applications have a "K" in the name, mostly as an initial letter and capitalized. However, there are notable exceptions like kynaptic, whose K is not capitalized, and Amarok. The K in many KDE applications is obtained by spelling a word which originally begins with C or Q differently, for example Konsole (which, incidentally, is correct spelling in German) and Kuickshow. Also, some just prefix a commonly used word with a K, for instance KOffice. Some applications do not have a K in the name at all, such as Gwenview. This seems to be an increasing trend among KDE 4 applications and technologies.
The KDE project's mascot is a green dragon named Konqi.
[edit] Development
KDE is built with Trolltech's Qt toolkit which runs on most Unix and Unix-like systems, Mac OS X and Microsoft Windows. Both KDE and GNOME now participate in freedesktop.org, an effort to standardize Unix desktop interoperability, although there is still some competition between them.[12]
[edit] Release cycle
| Timeline of major releases | |
|---|---|
| Date | Release |
| KDE 1 | |
| 14 October 1996 | Project announced by Matthias Ettrich[13] |
| 12 July 1998 | KDE 1.0 released[5] |
| 6 February 1999 | KDE 1.1 released[14] |
| KDE 2 | |
| 23 October 2000 | KDE 2.0 released[7] |
| 26 February 2001 | KDE 2.1 released[15] |
| 15 August 2001 | KDE 2.2 released[16] |
| KDE 3 | |
| 3 April 2002 | KDE 3.0 released[17] |
| 28 January 2003 | KDE 3.1 released[18] |
| 3 February 2004 | KDE 3.2 released[19] |
| 19 August 2004 | KDE 3.3 released[20] |
| 16 March 2005 | KDE 3.4 released[21] |
| 29 November 2005 | KDE 3.5 released[22] |
| KDE 4 | |
| 11 January 2008 | KDE 4.0 released[23] |
The KDE team releases new versions on a regular basis.
[edit] Platform releases
Platform releases are major releases that begin a series (version number X.0). These releases are allowed to break both binary and source-compatibility with the predecessor, or to put it differently, all following releases (X.1, X.2, ...) will guarantee source compatibility (API). This means, for instance, that software that was developed for KDE 3.0 will work on all (future) KDE 3 releases, in contrast to an application that was developed for KDE 2, which is not guaranteed to be able to make use of the KDE 3 libraries. KDE major version numbers follow the Qt release cycle meaning that KDE 4 is based on Qt 4, while KDE 3 was based on Qt 3.
[edit] Standard releases
There are two main types of releases, major releases and maintenance releases.
Major releases (with two version numbers, for example 3.5) contain new features. As soon as a major release is ready and announced, work on the next major release starts. A major release needs several months to be finished and many bugs that are fixed during this time are backported to the stable branch, meaning that these fixes are incorporated into the last stable release by maintenance releases.
Maintenance releases have three version numbers, e.g. KDE 1.1.1, and focus on fixing bugs, minor glitches and making small usability improvements. Maintenance releases in general do not allow new features although some releases include small enhancements. A shortened release schedule is used.
[edit] Applications
Major applications for KDE include:
- Amarok - Audio player
- K3b - Optical disc authoring software
- Kate - Text editor
- KDevelop - Integrated development environment
- Konsole - Terminal emulator
- Kontact - Personal information manager featuring an e-mail client, a news client, a feed aggregator, To-do lists and more.
- Kopete - Instant messaging client
- Konqueror - File manager and web browser
- KOffice - Office suite
For more applications, see list of KDE applications.
[edit] Base technologies
- KDELibs
- KHTML - HTML engine
- KIO - extensible network-transparent file access
- Kiosk - allows disabling features within KDE to create a more controlled environment
- KParts - lightweight in-process graphical component framework
- KWin - window manager
- XMLGUI - allows defining UI elements such as menus and toolbars via XML files
- Technologies added in KDE 4
- Plasma - desktop and panel widget engine
- Phonon - multimedia framework
- Solid - device integration framework
- Sonnet - spell checker
- ThreadWeaver - library to more effectively use multiprocessor systems
- Technologies superseded in KDE 4
- aRts - sound server (replaced with Phonon)
- DCOP - inter-process communication system (replaced with D-Bus)
[edit] Toolkit licensing
Qt, to which native graphical KDE applications link for their graphical widgets, is free software, dual-licensed under the GNU GPL versions 2 and 3, and QPL licenses. Trolltech also sell licenses for developing proprietary software. When using the free versions, programs which link to Qt must be released as free software (under the GPL or another license permitted by the QPL, such as the BSD or LGPL for example).
It is not necessary to use Qt or the KDE libraries to write software which integrates well with the KDE desktop. Software using any other toolkit, following the freedesktop.org standards or using KDE facilities such as KPrinter and KDialog can integrate nicely with the KDE desktop (both KPrinter and KDialog link to Qt, and are under the GPL), however the widgets will not have the exact behavior of Qt widgets. Additional integration efforts are being discussed in the Portland Free Desktop initiative,[24] and are planned for KDE 4.
Some other free/open source desktop platforms (such as GNOME, Xfce and EDE) use toolkits licensed under the LGPL. The LGPL permits proprietary/closed source applications to link to libraries licensed under the LGPL, with some restrictions: the Section 6 of the LGPL v2.1 prohibits linking to software with a license that restricts reverse-engineering and modification of the work for the customer's own use.[25] The proprietary Qt license which Trolltech sells does not carry these restrictions.
[edit] See also
[edit] Notes and references
- ^ KDE Licensing Policy
- ^ (14 October 1996). "New Project: Kool Desktop Environment (KDE)". de.comp.os.linux.misc. (Web link). Retrieved on 2006-12-29.
- ^ COSE Update FYI. Retrieved on 2007-09-25.
- ^ Bug#26414: incorrect tip KDE acronym. Retrieved on 2007-08-08.
- ^ a b KDE 1.0 Release Announcement. Retrieved on 2008-03-27.
- ^ KDE Free Qt Foundation. Retrieved on 2007-01-26.
- ^ a b c KDE 2.0 Release Announcement
- ^ NEPOMUK-KDE
- ^ Sponsorship Thanks. Retrieved on 2006-10-16.
- ^ Mark Shuttleworth Becomes the First Patron of KDE. KDE (15 October 2006). Retrieved on 2006-10-16.
- ^ Intel and Novell Become Patrons of KDE. KDE (July 7, 2007). Retrieved on 2007-07-08.
- ^ A tale of two desktops
- ^ Matthias Ettrich original posting
- ^ KDE News Archive for February 1999 referring to the release of version 1.1
- ^ KDE press release for version 2.1
- ^ KDE press release for version 2.2
- ^ KDE press release for version 3.0
- ^ KDE press release for version 3.1
- ^ KDE press release for version 3.2
- ^ KDE press release for version 3.3
- ^ KDE press release for version 3.4
- ^ KDE press release for version 3.5
- ^ KDE 4.0 Release Schedule. Retrieved on 2007-12-01.
- ^ A portland Wiki - Portland. Retrieved on 2006-08-26.
- ^ GNU Lesser General Public License. Retrieved on 2007-01-26.
[edit] External links
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