KDE Platform 4 was a collection of

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 ...

and

software framework In computer programming, a software framework is a software abstraction that provides generic functionality which developers can extend with custom code to create applications. It establishes a standard foundation for building and deploying soft ...

s by

KDE KDE is an international free software community that develops free and open-source software. As a central development hub, it provides tools and resources that enable collaborative work on its projects. Its products include the KDE Plasma gra ...

that served as technological foundation for

KDE Software Compilation 4 KDE Software Compilation 4 (KDE SC 4) was the only series of the so-called KDE Software Compilation (KDE SC), first released in January 2008. The final release was version 4.14.3 in November 2014. It was the follow-up to K Desktop Environment 3 ...

distributed under the

GNU Lesser General Public License The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own ...

(LGPL). KDE Platform 4 was the successor to KDElibs and the predecessor of

KDE Frameworks KDE Frameworks is a collection of Library (computing), libraries and software frameworks readily available to any Qt (software), Qt-based software stacks or applications on multiple operating systems. Featuring frequently needed functionality sol ...

. KDE Platform 4 is the only version of KDE Platform, and in 2013 it was replaced by

KDE Frameworks 5 KDE Frameworks is a collection of Library (computing), libraries and software frameworks readily available to any Qt (software), Qt-based software stacks or applications on multiple operating systems. Featuring frequently needed functionality sol ...

Technologies

* User Interface ** Plasma – desktop and panel widget engine **

KHTML KHTML is a discontinued browser engine that was developed by the KDE project. It originated as the engine of the Konqueror browser in the late 1990s, but active development ceased in 2016. It was officially discontinued in 2023. Built on the ...

– HTML rendering engine **

KIO KIO (KDE Input/Output) is a system library incorporated into KDE Frameworks and KDE Software Compilation 4. It provides access to files, web sites and other resources through a single consistent API. Applications, such as Konqueror and Dolph ...

– extensible network-transparent file access **

KParts KDE Frameworks is a collection of libraries and software frameworks readily available to any Qt-based software stacks or applications on multiple operating systems. Featuring frequently needed functionality solutions like hardware integration, f ...

– lightweight in-process graphical component framework **

Sonnet A sonnet is a fixed poetic form with a structure traditionally consisting of fourteen lines adhering to a set Rhyme scheme, rhyming scheme. The term derives from the Italian word ''sonetto'' (, from the Latin word ''sonus'', ). Originating in ...

– spell checker **

XMLGUI XMLGUI is a KDE framework for designing the user interface of an application using XML, using the idea of actions. In this framework, the programmer designs various actions that their application can implement, with several actions defined for th ...

– allows defining UI elements such as menus and toolbars via

XML Extensible Markup Language (XML) is a markup language and file format for storing, transmitting, and reconstructing data. It defines a set of rules for encoding electronic document, documents in a format that is both human-readable and Machine-r ...

files **

Goya Francisco José de Goya y Lucientes (; ; 30 March 1746 – 16 April 1828) was a Spanish romantic painter and printmaker. He is considered the most important Spanish artist of the late 18th and early 19th centuries. His paintings, drawings, an ...

* Hardware and Multimedia **

Phonon A phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, specifically in solids and some liquids. In the context of optically trapped objects, the quantized vibration mode can be defined a ...

– multimedia framework **

Solid Solid is a state of matter where molecules are closely packed and can not slide past each other. Solids resist compression, expansion, or external forces that would alter its shape, with the degree to which they are resisted dependent upon the ...

– device integration framework * Services **

NEPOMUK Nepomuk (; ) is a town in Plzeň-South District in the Plzeň Region of the Czech Republic. It has about 3,600 inhabitants. It is known as the birthplace of Saint John of Nepomuk, who was born here around 1340. Administrative division Nepomuk ...

KNewStuff KDE Frameworks is a collection of libraries and software frameworks readily available to any Qt-based software stacks or applications on multiple operating systems. Featuring frequently needed functionality solutions like hardware integration, f ...

– KDE's "Hot New Stuff" classes ** Policykit-KDE * Communication **

Akonadi Akonadi is a storage service for personal information management (PIM) data and metadata named after the oracle goddess of justice in Ghana. It is one of the “pillars” (core technologies) behind the KDE SC 4 project, although it is designed t ...

* Games **

Gluon A gluon ( ) is a type of Massless particle, massless elementary particle that mediates the strong interaction between quarks, acting as the exchange particle for the interaction. Gluons are massless vector bosons, thereby having a Spin (physi ...

** KGGZ * Other **

ThreadWeaver ThreadWeaver is a system library initially developed for KDE Software Compilation 4 and later refactored for KDE Frameworks 5. ThreadWeaver allows developers to easily take advantage of multi-core processors and multithreading. In ThreadWeaver th ...

– library to use multiprocessor systems more effectively **

Kiosk Historically, a kiosk () was a small garden pavilion open on some or all sides common in Iran, Persia, the Indian subcontinent, and in the Ottoman Empire from the 13th century onward. Today, several examples of this type of kiosk still exist ...

– allows disabling features within KDE to create a more controlled environment ** Kross ** KConfig XT **

WebDAV WebDAV (Web Distributed Authoring and Versioning) is a set of extensions to the Hypertext Transfer Protocol (HTTP), which allows user agents to collaboratively author contents ''directly'' in an HTTP web server by providing facilities for conc ...

Technologies superseded in KDE Platform 4

aRts The arts or creative arts are a vast range of human practices involving creativity, creative expression, storytelling, and cultural participation. The arts encompass diverse and plural modes of thought, deeds, and existence in an extensive ...

–

sound server A sound server is software that manages the use of and access to audio devices (usually a sound card). It commonly runs as a background process. Sound server in an operating system In a Unix-like operating system, a sound server mixes differen ...

(replaced with

) * DCOP –

inter-process communication In computer science, interprocess communication (IPC) is the sharing of data between running Process (computing), processes in a computer system. Mechanisms for IPC may be provided by an operating system. Applications which use IPC are often cat ...

system (replaced with

D-Bus D-Bus (short for "Desktop Bus") is a message-oriented middleware mechanism that allows communication between multiple Process (computing), processes running concurrently on the same machine. D-Bus was developed as part of the freedesktop.org pro ...

)

KParts

KParts is the

component Component may refer to: In engineering, science, and technology Generic systems *System components, an entity with discrete structure, such as an assembly or software module, within a system considered at a particular level of analysis * Lumped e ...

framework for the

KDE Plasma KDE Plasma is a Shell (computing), graphical shell developed by the KDE community for Unix-like operating systems. It serves as the interface layer between the user and the operating system, providing a graphical user interface (GUI) and workspa ...

desktop environment In computing, a desktop environment (DE) is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system that share a common graphical user interface (GUI), sometimes described as a graphi ...

. An individual component is called a KPart. KParts are analogous to

Bonobo The bonobo (; ''Pan paniscus''), also historically called the pygmy chimpanzee (less often the dwarf chimpanzee or gracile chimpanzee), is an endangered great ape and one of the two species making up the genus ''Pan (genus), Pan'' (the other bei ...

components in

GNOME A gnome () is a mythological creature and diminutive spirit in Renaissance magic and alchemy, introduced by Paracelsus in the 16th century and widely adopted by authors, including those of modern fantasy literature. They are typically depict ...

and

ActiveX ActiveX is a deprecated software framework created by Microsoft that adapts its earlier Component Object Model (COM) and Object Linking and Embedding (OLE) technologies for content downloaded from a network, particularly from the World Wide W ...

controls in Microsoft's

Component Object Model Component Object Model (COM) is a binary-interface technology for software components from Microsoft that enables using objects in a language-neutral way between different programming languages, programming contexts, processes and machines ...

Konsole Konsole is a free and open-source terminal emulator graphical application which is part of KDE Applications and ships with the KDE desktop environment. Konsole was originally written by Lars Doelle. It ls licensed under the GPL-2.0-or-later and t ...

is available as a KPart and is used in applications like

Konqueror Konqueror is a Free and open-source software, free and open-source web browser and file manager that provides World Wide Web, web access and file viewer, file-viewer functionality for file systems (such as local files, files on a remote FTP ser ...

and

Kate Kate may refer to: People and fictional characters * Kate (given name), a list of people and fictional characters with the given name or nickname * Gyula Káté (born 1982), Hungarian amateur boxer * Lauren Kate (born 1981), American author o ...

. Example uses of KParts: *

uses the

Okular Okular is a free and open source multiplatform document viewer developed by the KDE community based on the Qt and KDE Frameworks libraries. It is distributed as part of the KDE Applications bundle. It replaced KPDF, its main predecessor, alongsi ...

part to display documents *

uses the Dragon Player part to play multimedia *

Kontact Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email. It offers a number of inter-changeable graphical UIs (KMail, KAddressBook, Akregator, ...

embeds

kdepim Kontact is a personal information manager and groupware software suite developed by KDE. It supports calendars, contacts, notes, to-do lists, news, and email. It offers a number of inter-changeable graphical UIs (KMail, KAddressBook, Akregator, ...

applications *

and other editors use the katepart editor component * Several applications use the

KPart to embed a terminal

Solid

Solid is a device integration framework for KDE Platform 4 and its successor,

. It functions on similar principles to KDE's multimedia pillar

; rather than managing hardware on its own, it makes existing solutions accessible through a single API. The current solution uses

udev udev (userspace ) is a device manager for the Linux kernel. As the successor of devfsd and hotplug, udev primarily manages device nodes in the directory. At the same time, udev also handles all user space events raised when hardware devices ...

NetworkManager NetworkManager is a daemon that sits on top of libudev and other Linux kernel interfaces (and a couple of other daemons) and provides a high-level interface for the configuration of the network interfaces. Rationale NetworkManager is a software ...

and

BlueZ A Bluetooth stack is software that is an implementation of the Bluetooth protocol stack. Bluetooth stacks can be roughly divided into two distinct categories: # ''General-purpose'' implementations that are written with emphasis on feature-richn ...

(the official

Linux Linux ( ) is a family of open source Unix-like operating systems based on the Linux kernel, an kernel (operating system), operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically package manager, pac ...

Bluetooth stack). However, any and all parts can be replaced without breaking the application, making applications using Solid extremely flexible and portable. Work is underway to build a Solid backend for the

Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

port of KDE based on

Windows Management Instrumentation Windows Management Instrumentation (WMI) is a set of extensions to the Windows Driver Model that provides an operating system interface through which instrumented components provide information and notification. WMI is Microsoft's implementatio ...

References

External links

TechBase
documentation for KDE developers
KDE Projects
overview of all projects within git.kde.org
KDE quick Git source code browser

KDE Bug Tracking System

KDE tutorial first program
{{KDE Application programming interfaces Articles with example C++ code Computing platforms Free computer libraries KDE software Unix windowing system-related software X-based libraries