KDE

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K Desktop Environment
A screenshot of KDE 3.5 running the Kontact personal information manager and Konqueror file manager
Developer:	The KDE Team
Latest release:	3.5.6 / January 25, 2007
OS:	Cross-platform
Use:	Desktop environment
License:	GNU General Public License and others
Website:	http://www.kde.org/

KDE (K Desktop Environment) (IPA: [ke.di.i]) is a free software project which aims to be a powerful ecosystem 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 ecosystem. In this regard the KDE project serves as an umbrella project for many standalone applications and smaller projects that are based on KDE technology, such as KOffice, KDevelop, Amarok and K3b.

The KDE logo is a "K" over a cogwheel and the project's mascot is a green dragon named Konqi. Konqi can be found in various applications, including when the user logs out and in the "About KDE" screen.

[edit] History

Konqi KDE project mascot

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 were 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.^[1] The name KDE was intended as a word play on the existing Common Desktop Environment available for Unix systems. The K was originally suggested to stand for "Kool", but it was quickly decided that the K should stand for nothing in particular.^[2]

Matthias chose to use the Qt toolkit for the KDE project. Other programmers quickly started developing KDE/Qt applications, and by early 1997, large and complex 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. 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.

In November 1998, the Qt toolkit was licensed under the free/open source Q Public License (QPL). This same year the KDE Free Qt foundation ^[3] 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. But debate continued about compatibility with the GNU General Public License (GPL). In September 2000, Trolltech made the Unix version of the Qt libraries available under the GPL, in addition to the QPL, which has eliminated the concerns of the Free Software Foundation. Starting with the release of Qt 4.0, it is available as free software for the Unix, Mac and Windows platforms, indicating that the next major version of KDE applications and libraries will have native support on these platforms.

Both KDE and GNOME now participate in Freedesktop.org, an effort to standardize Unix desktop interoperability, although there is still some friendly competition between them.

[edit] Organization of the KDE project

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 discussions (such as the question of whether the KDE 2 API should be broken in favour of KDE 3) are rare.

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] Release cycle and version numbers

Typical SuSE KDE desktop running daily common applications.

As the project history below shows, the KDE team releases new versions on a frequent basis. It is rare that a release is delayed for more than one or two weeks. An exception was KDE 3.1, which was delayed for more than a month because of a number of security issues in the code base.

There are two main types of releases, major releases and minor releases.

[edit] Major release

There have been 11 major releases so far: 1.0, 1.1, 2.0, 2.1, 2.2, 3.0, 3.1, 3.2, 3.3, 3.4 and 3.5. The next major release will be KDE 4.0, which has been scheduled for release on October 23, 2007 (see the KDE4 roadmap).

The KDE X.0 releases are special, as they 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 binary (ABI) and 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.

The changes between KDE 1 and KDE 2 series were large and many, while the API changes between KDE 2 and KDE 3 were comparatively minor, meaning that applications could be more easily ported to the new architecture. Up to now the KDE major version numbers follow the Qt release cycle.

Besides the special X.0 releases, a major release will allow new features. Minor releases in general don't allow new features although some releases in the 3.5.x line have had minor enhancements.

A customized KDE desktop, running with transparency. Shown with KSmoothdock, and GKrellM.

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.

The current major release is 3.5, which arrived on November 29, 2005. KDE 4 will succeed 3.5 sometime in the third quarter of 2007 and will be based on Qt 4.x encompassing some major changes to the desktop.

[edit] Minor release

A minor KDE release has three version numbers, e.g. KDE 1.1.1, and a focus on fixing bugs, minor glitches and making small usability improvements, as opposed to adding new features. For minor releases, a shortened release schedule is used.

[edit] KDE 4

This article or section contains information about scheduled or expected future software. The content may change dramatically as the software release approaches and more information becomes available.

Early screenshot of KDE 4 running Kate. KDE 4 will take on a completely different GUI than the one shown, as features such as Plasma are integrated into the desktop.

KDE 4 will be a major revision of KDE, based on the version 4 series of Qt. Its release date has been scheduled for October 23, 2007. Some of the planned features are explained here: ^{[4] [5]}. On August 18, 2006, a minimal technical preview of KDE4, KDE 3.80.1 was released ^[6] and the first Technical Preview version of KDE 4 is due to be released to coincide with KDE's tenth birthday, a culmination of all the KDE 4 hacking that took place at aKademy 2006 in Dublin. ^[7]

• Faster and more memory efficient, due to the greater speed and efficiency of Qt 4.x and increased efficiency in the KDE libraries themselves.
• Reorganized and cleaned up core kdelibs API and rewritten Human Interface Guidelines.
• A new default icon theme and visual guidelines, developed by the Oxygen Project, which will make extensive use of SVG.
• A completely redesigned desktop and panels collectively called Plasma which will integrate Kicker, KDesktop, and SuperKaramba and is intended to update the decades-old desktop metaphor which defines the modern computing experience.
• Streamlined file management and web browsing interfaces in Konqueror.
• A standard scripting system centered around ECMAScript (which is JavaScript) or Kross which is a language-independent solution developed and used in KOffice. It now supports python and ruby, but more are to come.
• A new multimedia interface (Phonon), making KDE independent of any one specific media framework.
• An API for network and portable devices, called Solid.
• A new communication framework (Decibel).
• A metadata and search framework, probably named Tenor. It might incorporate Strigi as a full-text file indexing service, and Nepomuk with KDE integration
• A new default file manager Dolphin
• Porting libraries needed by KDE applications to Windows and Mac OS X so KDE applications will easily be ported to Windows and Mac OS X. ^[8]
• A new spell checking software called Sonnet with automatic language detection. It will replace kspell to mark misspellings in text input fields in KDE based applications. Advantages over kspell are the automatic language detection and the ability to work even if several languages are mixed in one document.

[edit] Architecture

KDE is built with Trolltech's Qt toolkit which runs not only on most Unix and Unix-like systems, but also on Mac OS X and Microsoft Windows. All releases of KDE 3 are build upon Qt version 3.x, which was only released under the GPL licence for Linux and Unix-like operating systems, including Mac OS X. For that reason, KDE 3 is only available on Windows through ports involving a X server.

KDE 4 will be based on Qt 4.x which is also released under the GPL for Windows and Mac OS. Therefore KDE 4 applications can run native on these operating systems as well.

[edit] Base technologies used in KDE 3

• aRts - soundserver
• DCOP - system for communication between processes
• KHTML - HTML engine
• KIO - extensible network-transparent file access for KDE applications
• Kiosk - disable features within KDE to create a more controlled environment
• KParts - lightweight in-process graphical component framework
• KWin - window manager
• KConfigXT - takes an XML file and produces source code to manage configuration options, including classes to glue the resulting code to configuration dialogs.
• XMLGUI - allows defining UI elements such as menus and toolbars via XML files

[edit] Packaging

A minimalist KDE desktop using the Nuvola icons.

KDE 3.5.4 running the Baghira theme, with OS-L-IconSet, fonts, and KSmoothDock.

Due to the size of KDE, it is divided into several package categories to simplify installation. This is a reference scheme; packagers are free to use their own packages for KDE.

• aRts - KDE sound server.
• kdelibs - Primary libraries, containing most pieces of KDE architecture.
• kdebase - The base desktop and applications. Requires kdelibs.
• kdeaccessibility - Accessibility software.
• kdeaddons - Add-on software.
• kdeadmin - Administrative tools, intended for administering UNIX machines.
• kdeartwork - Additional artwork (widget style, screensavers, wallpapers, etc...)
• kdeedu - Educational software.
• kdegames - Games.
• kdegraphics - Tools for manipulating graphics.
• kde-i18n - Internationalization for KDE.
• kdemultimedia - Multimedia software.
• kdenetwork - Network tools and software.
• kdepim - Personal information management and E-mail software.
• kdesdk - Developer tools.
• kdetoys - Desktop Toys and Amusements.
• kdeutils - Utilities.
• kdewebdev - Web Development.
• koffice - Office suite.
• kdebindings - Support for other programming languages

There is also a Subversion module, Extragear (utils, network, multimedia... applications), which is used by applications which are part of the KDE project but don't depend on the release cycle of the main codebase; K3b and Amarok are part of this module. More info can be found on the homepage.

[edit] Major KDE applications

For a full list, see list of KDE applications. Applications for KDE include:

• Amarok - Audio player, podcast and iPod compatible
• Akregator - RSS feed reader
• K3b - CD and DVD burning application
• Kate - Text editor
• KDevelop - Integrated Development Environment (IDE)
• KMail - Email client
• Knode - Newsgroup reader
• Konsole - Terminal emulator
• Kopete - Instant messaging
• Konqueror - File manager and web browser using KHTML
• KPlayer - Multimedia player and library
• KPresenter - Presentation application
• KSpread - Spreadsheet
• KWord - Word processor
• KWrite - Light weight text editor with syntax highlights and other features
• TaskJuggler - Project management software

[edit] Timeline

• 14 October 1996: Project was announced by Matthias Ettrich.^[9]
• 12 July 1998: KDE 1.0 released^[10]
• 6 February 1999: KDE 1.1 released^[11]
  • 3 May 1999: KDE 1.1.1 released^[12]
  • 13 September 1999: KDE 1.1.2 released^[13] (KDE 1.2 was planned, but never released^[14],^[15],^[16])
• 15 December 1999: KDE 1.89, aka Krash (unstable developers' release)
• 23 October 2000: KDE 2.0 released
• 26 February 2001: KDE 2.1 released
• 15 August 2001: KDE 2.2 released
• 3 April 2002: KDE 3.0 released
• 28 January 2003: KDE 3.1 released
• 3 February 2004: KDE 3.2 released
• 19 August 2004: KDE 3.3 released
• 16 March 2005: KDE 3.4 released
• 29 November 2005: KDE 3.5 released
  • 31 January 2006: KDE 3.5.1 released
  • 28 March 2006: KDE 3.5.2 released
  • 31 May 2006: KDE 3.5.3 released
  • 02 August 2006: KDE 3.5.4 released
  • 11 October 2006: KDE 3.5.5 released
  • 24 January 2007: KDE 3.5.6 released
• 23rd October 2007: expected release date for KDE4

[edit] Naming convention

Most 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, Gwenview, which doesn't have a K in the name at all, and Amarok which formerly had its final k capitalized. The K in many KDE applications is obtained by spelling a word which originally begins with C or Q differently, for example Konsole and Kuickshow. Also, some just prefix a commonly used word with a K, an instance being KOffice.

[edit] Licensing issues

Qt, to which native graphical KDE applications link for their graphical widgets, is free software, licensed under the GNU GPL and QPL licenses (a license for developing proprietary software may be purchased however). When using the free versions, programs which link to Qt must be released as FOSS (under the GPL or another license permitted by the QPL, such as the BSD or LGPL for example). After the release of Qt under the GPL, the controversy over licensing with the Free Software Foundation ended.

Some developers of proprietary/closed source software argue that paying for a license, similar to the relatively expensive development tools of other systems, removes most of the financial incentive for writing proprietary/closed source, native graphical KDE applications. However, 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 ^[17], 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 ^[18]. The commercial proprietary Qt license does not carry these restrictions.

[edit] Usability

KDE aims to make easy-to-use programs without sacrificing features. KDE's Usability page states its goal as: "Working within the existing design goals of a system, usability efforts aim to make the implementations of these designs easier to use, faster to learn, more consistent and obvious, and generally more ergonomic for their target audience." ^[19] To improve the user interface, work has gone into reducing visual complexity for versions 3.2 to 3.5. The most promising effort is the close work with the OpenUsability Project. One of the major goals of KDE 4.0 is to identify further areas that are lacking from a usability perspective and address these concerns. In particular, new human interface guidelines are being developed for KDE 4.0.

KDE strives to make otherwise onerous or difficult tasks easier, such as adding printers (local or networked), setting up 802.11 Wireless security settings (such as WEP), and installing new fonts and window decorations. Third-party web sites LinuxPrinting and KDE-Look support KDE through adding devices or customizing the environment's look and feel.

[edit] Criticisms

The KDE interface has been criticised for being too complex and including too many configurable options. However, a usability report ^[20] evaluating a customized version of KDE 3.1 showed, as early as 2003, that Windows users quickly became familiar with KDE, enjoyed it and were able to accomplish the proposed task as quickly as with Windows XP.

[edit] Sponsorship

The KDE project and related events are frequently sponsored by individuals, universities, and businesses such as Dell and IBM.^[21]

On 15 October 2006 it was announced that Mark Shuttleworth became the first patron of KDE, the highest level of sponsorship available.^[22]

[edit] See also

Free software Portal

• List of Unix programs
• Comparison of X Window System desktop environments
• GNOME

[edit] Notes and references

[edit] External links

Wikibooks has more about this subject:

Using KDE

• The KDE website
• KDE.News, the KDE news site