The Harmony toolkit is a never-completed

free software Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, ...

widget toolkit A widget toolkit, widget library, GUI toolkit, or UX library is a library or a collection of libraries containing a set of graphical control elements (called ''widgets'') used to construct the graphical user interface (GUI) of programs. Most wid ...

that aimed to be API compatible with the then non- freely licensed Qt widget toolkit. The QPL license that Qt used was free only if the program was not sold for profit and if its source code was freely available. It was later released under the terms of 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). In addition to source compatibility with Qt, the Harmony project also aimed to add functionality such as multi-threaded applications and pluggable themes, features that Qt itself later added. The

GNU Project The GNU Project () is a free software, mass collaboration project announced by Richard Stallman on September 27, 1983. Its goal is to give computer users freedom and control in their use of their computers and Computer hardware, computing devi ...

launched the Harmony project, and also the GNOME desktop project, to counter the perceived problem that the free software KDE desktop was gaining popularity but was requiring that people install

proprietary software Proprietary software is computer software, software that is deemed within the free and open-source software to be non-free because its creator, publisher, or other rightsholder or rightsholder partner exercises a legal monopoly afforded by modern ...

. In July 1997 the GNU Project called for volunteers for a Qt replacement in GNU's Bulletin and listed it as a top priority task on its website. Development ceased at the end of 2000, when Qt was released under the GPL, removing the perceived need for the Harmony Project to exist. In January 2009 Qt itself was made available under the GNU LGPL, along with the previous license options.

References

External links

The GNU project
an essay by Richard Stallman, telling the story of Qt, Harmony, and GNOME
Harmony / FreeQt mailing list

Qt and the LSB
mostly tangential information about Qt licensing {{DEFAULTSORT:Harmony (Toolkit) KDE Widget toolkits X-based libraries