Qt, a grafikus felhasználói felület (GUI), amit a KDE alkalmazások készítésére használtak nem állt egy teljesen nyílt forráskódú licenc alatt, ugyanis a fejlesztő Trolltechnek volt egy kereskedelmi ága. A fő következményei ennek azok voltak, hogy a KDE-hez szabadalmazott (proprietrary) szoftver készítéséhez szükség volt egy licencre a Trolltech-től, és minden Qt fejlesztésnek a Trolltech-en keresztül kellett folynia. A KDE egy nyílt forráskódú projekt, ezért a Qt választásának helyessége mint GUI toolkit vita tárgyát képezi az open-source puristák közt. A Trolltech később GPL licenc alá helyezte a Qt-t, ezzel a vita tárgytalanná vált, ez mégis fontos részét képezi a KDE történetének.
To tackle this problem, the KDE Free Qt Foundation was founded by the KDE project and Trolltech. This foundation ensured the continued availability of Qt as a free software development framework. Namely, should Trolltech no longer make Qt available for free software, the currently released version will be re-released under the BSD style license - a license similar in nature but less restrictive than the GPL or LGPL.
This decision to re-release would be moderated by a team of 2 members representing the KDE foundation (unaffiliated with Trolltech) and 2 members from Trolltech to vote. In case of a tie, the KDE vote will gain higher weighting.
Those who prioritised the release of an GPL licensed formed the Harmony project - a project to clone Qt under a GPL license. Rapid progress was made during its time and thus gave purists no excuse to reject KDE as a respectable and compliant desktop environment. However this project was depreciated as Trolltech made the decision to re-license Qt under the GPL.
12 July 1998 - KDE 1.0 Announcement "An integrated Desktop Environment for the Unix Operating System. We are pleased to announce the availability of release 1.0 of the KDesktop Environment"
23 October 2000 - KDE 2.0 released "The KDE Team today announced the release of KDE 2.0, KDE's powerful, modular, Internet-enabled desktop. This highly anticipated release constitutes the next generation of the award-winning KDE 1 series, which culminated in the release of KDE 1.1.2 just over a year ago. KDE 2.0 is the work product of hundreds of dedicated developers originating from over 30 countries. "
17 December 2001 - KOffice 1.1.1 Released "Currently KOffice has functionality well-suited for home and SOHO users, who generally write letters, faxes, memos and similar documents. KOffice 1.1.1 is a minor update release for KOffice 1.1."
3 April 2002 - KDE 3.0 Released "KDE 3.0 is a major step for the KDE project. A hundred words could be written here, but to stop boring you with details, lets just say: Check it out!"
11th May 2007 - KDE 4.0 Alpha 1 Released "KDE Project Ships First Alpha Release for Leading Free Software Desktop."
16th October 2007 - KDE 3.5.8 Released "Project Ships Eighth Translation and Service Release for Leading Free Software Desktop."
11th January 2008 - KDE 4.0 Released "KDE Community Ships Fourth Major Version for Leading Free Software Desktop."
19th February 2008 - KDE 3.5.9 Released "KDE Community Ships Ninth Maintenance Update for Third Major Version for Leading Free Software Desktop."
29th July 2008 - KDE 4.1 Released "KDE Community Ships Major Update to Leading Free Software Desktop."
26th August 2008 - KDE 3.5.10 Released "KDE Community Ships Tenth Maintenance Update for Third Major Version for Leading Free Software Desktop."
12th October 2008 - KDE Forum Launched "KDE Launches Web-based Bulletin Board."
27th January 2009 - KDE 4.2.0 Released "KDE Community Ships Second Major Update To Leading Free Software Desktop."
4th August 2009 - KDE 4.3.0 Released "KDE Community Ships Third Update to the KDE 4 Desktop, Applications and Platform."
9th February 2010 - KDE SC 4.4.0 Released "KDE announces the immediate availability of the KDE Software Compilation 4.4, "Caikaku", bringing an innovative collection of applications to Free Software users."
10th August, 2010 - KDE 4.5.0 released Focusing on "stability, the overall polish and performance gain".
26th January 2011 - KDE SC 4.6.0 Released Major updates to the KDE Plasma workspaces, KDE Applications and KDE Platform
27th July 2011 - KDE 4.7.0 released Containing compelling new features and improvements to the Plasma Workspaces, the KDE Applications and the KDE Development Platform
9th October 2011 - Plasma Active One Arrived First KDE version of cross-device UX.
14th December 2011 - Plasma Active Two Released Second version of cross-Device UX, boosting performance and adding new features.
25th January 2012 - KDE 4.8 Released Gaining adaptive power management, offering faster and more scalable file management, enhancing interoperability and introducing touch-friendly components.
1st August 2012 - KDE 4.9 Released Providing many new features, along with improved stability and performance. Dedicated to the memory of KDE contributor Claire Lotion.
15th October 2012 - Plasma Active 3 Released Improving performance and bringing new applications.
6th February 2013 - KDE 4.10 Released Improving mobile device support, opening up more APIs to Qt Quick and improving performance and usability.
14th August 2013 - KDE 4.11 Released Refined user experience, PIM improvements, better performance.
5th September 2013 - Plasma Active 4 Released Improving overall performance and usability.
18th December 2013 - KDE Applications and Development Platforms Released Bring Huge Step Forward in Personal Information Management and Improvements All Over.
For a more detailed look at the history, including details of all the KDE 3.x releases, see this page