# KDE Software Compilation 4

> former umbrella term by KDE for the Plasma 4.x desktop environment bundled with an associated range of applications produced by KDE

**Wikidata**: [Q1346625](https://www.wikidata.org/wiki/Q1346625)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/KDE_Software_Compilation_4)  
**Source**: https://4ort.xyz/entity/kde-software-compilation-4

## Summary
KDE Software Compilation 4 (KDE SC 4) is a now-discontinued suite of free software developed by KDE that included the Plasma 4.x desktop environment and a wide array of associated applications. It was released under multiple open-source licenses including the GNU GPL and served as the primary offering from KDE between 2008 and 2014. This compilation marked a major transition in KDE's approach to desktop environments and application development.

## Key Facts
- Released under the GNU General Public License, GNU Lesser General Public License, BSD licenses, and MIT License.
- The final stable version was 4.14.3, released on November 11, 2014.
- Followed K Desktop Environment 3 and preceded KDE Frameworks and KDE Gear.
- Included KDE Plasma 4 as its core desktop environment component.
- Developed primarily using the Qt framework (C++ programming language).
- Featured aliases such as KDE 4, KDE SC 4, and Arthur.
- Hosted at www.kde.org with branding assets like the Oxygen logo.
- Part of the broader KDE Software Compilation series, specifically numbered as version 4.

## FAQs
### Q: What is KDE Software Compilation 4?
A: KDE Software Compilation 4 is a discontinued set of free software tools created by KDE e.V., which includes the Plasma 4 desktop environment along with various productivity and utility applications. It was widely used in Linux distributions during the late 2000s and early 2010s.

### Q: When was KDE SC 4 released?
A: Development began around 2007, with the first official release occurring in January 2008. Subsequent updates were made over several years until the last version, 4.14.3, was released in November 2014.

### Q: Is KDE Software Compilation 4 still supported?
A: No, KDE SC 4 reached end-of-life after version 4.14.3 in November 2014. Support has since shifted to newer iterations like KDE Plasma 5 and later technologies such as KDE Frameworks and KDE Gear.

## Why It Matters
KDE Software Compilation 4 represented a pivotal era in the evolution of open-source desktop computing. As one of the most feature-rich and customizable desktop environments available for Linux-based systems, it played a central role in making Linux more accessible to general users while also providing developers with powerful tools for customization and extension. Its modular architecture allowed for integration across numerous platforms and contributed significantly to the growth of the FOSS ecosystem. By bundling essential applications—such as file managers, text editors, multimedia players, and office suites—it offered a complete user experience out-of-the-box. Although succeeded by newer generations, KDE SC 4 remains historically significant as a milestone in desktop interface design and community-driven software development.

## Notable For
- Introducing the visually refined "Oxygen" theme and iconography.
- Being among the first desktop environments to offer advanced compositing effects via XRender and OpenGL.
- Bundling a comprehensive suite of cross-platform applications built on the robust Qt toolkit.
- Pioneering modularity through tightly integrated but independently upgradable components.
- Serving as the foundation for many popular Linux distribution defaults throughout the early 2010s.

## Body
### Overview
KDE Software Compilation 4 was an umbrella term referring to the fourth generation of KDE’s integrated desktop environment and application suite. Initially launched in January 2008, it introduced substantial improvements in visual aesthetics, usability, and performance compared to its predecessor, KDE 3.

### Components and Architecture
At its core lay **KDE Plasma 4**, a redesigned shell responsible for managing the desktop workspace, panels, widgets (plasmoids), and system notifications. Alongside this, KDE SC 4 shipped with a full complement of applications including Dolphin (file manager), Konsole (terminal emulator), Kate (text editor), Amarok (music player), and Kontact (personal information manager).

The entire stack relied heavily on the **Qt framework** (version 4.x), enabling cross-platform compatibility and rich graphical capabilities. Modularization became a key architectural principle, allowing parts of the system to be updated without requiring full upgrades.

### Licensing and Distribution
All components within KDE SC 4 were distributed as **free software**, adhering to licenses such as the GNU General Public License (GPL), GNU Lesser General Public License (LGPL), BSD licenses, and MIT License. These permissive terms ensured broad adoption and modification rights for both individual users and commercial vendors.

Major Linux distributions—including Kubuntu, openSUSE, Fedora, and Debian—adopted KDE SC 4 as their default or optional desktop environment, cementing its influence in the open-source landscape.

### Versions and Lifecycle
Several incremental releases occurred throughout its lifecycle:
- Version **4.12** was released on December 18, 2013.
- Final stable release was **4.14.3**, published on November 11, 2014.

After reaching end-of-life, KDE transitioned focus toward splitting the monolithic structure into smaller, reusable libraries known collectively as **KDE Frameworks**, alongside standalone applications branded under **KDE Gear**.

### Legacy and Succession
Though no longer actively maintained, KDE SC 4 left behind a legacy of innovation in desktop interactivity and extensibility. Its concepts influenced future developments in KDE Plasma 5 and beyond, ensuring continuity in design philosophy and functionality.

## References

1. [Source](http://kde.org/announcements/4.12/)
2. [Source](http://dot.kde.org/2013/12/18/kde-releases-applications-and-development-platform-412)
3. [Source](http://techbase.kde.org/Schedules/KDE4/4.12_Release_Schedule)
4. [KDE Ships Applications and Platform 4.14.3. 2014](https://www.kde.org/announcements/announce-4.14.3.php)
5. Freebase Data Dumps. 2013