KDE, Qt, and Troll Tech

The case of KDE, Qt, and Troll Tech is relevant to this essay because the KDE group and Troll Tech tried to place a non-Open-Source product in the infrastructure of Linux, and met with unexpected resistance. Public outcry and the threat of a fully open-source replacement for their product eventually convinced Troll to switch to a fully Open Source license. It's an interesting example of the community's enthusiastic acceptance of the Open Source Definition that Troll Tech had to make its license comply, if their product was to succeed.

KDE was the first attempt at a free graphical desktop for Linux. The KDE applications were themselves under the GPL, but they depended on a proprietary graphical library called Qt, from Troll Tech. Qt's license terms prohibited modification or use with any display software other than the senescent X Window System. Other use required a $1,500 developer's license. Troll Tech provided versions of Qt for Microsoft Windows and the Macintosh, and this was its main revenue source. The pseudo-free license for X systems was meant to leverage the contributions of Linux developers into demos, examples, and accessories for their pricey Windows and Mac products.

Although the problems with the Qt license were clear, the prospect of a graphical desktop for Linux was so attractive that many users were willing to overlook its non-Open-Source nature. Open Source proponents found KDE objectionable because they perceived that the KDE developers were trying to blur the definition of what free software was to include partially-free items like Qt. The KDE developers contended that their programs were Open Source, even though there were no runnable versions of the programs that did not require a non-Open-Source library. I, and others, asserted that KDE applications were only Open Source fragments of non-Open-Source programs, and that an Open Source version of Qt would be necessary before KDE could be referred to as Open Source.

The KDE developers attempted to partially address the problem of Qt's license by negotiating a KDE Free Qt Foundation agreement with Troll Tech, in which Troll and KDE would jointly control releases of the free version of Qt, and Troll Tech would release Qt under an Open-Source-complaint license if the company was ever purchased or went out of business.

Another group initiated the GNOME project, a fully Open Source competitor of KDE that aimed to provide more features and sophistication, and a separate group initiated a Harmony project to produce a fully Open Source clone of Qt that would support KDE. As GNOME was being demonstrated to accolades and Harmony was about to become useful, Troll Tech realized Qt would not be successful in the Linux market without a change in license. Troll Tech released a fully Open Source license for Qt, defusing the conflict and removing the motivation for the Harmony project. The GNOME project continues, and now aims to best KDE in terms of functionality and sophistication rather than in terms of its license.

Before they released their new Open Source license, Troll Tech provided me with a copy for auditing, with the request that it be kept confidential until they could announce it. In my enthusiasm to make peace with the KDE group and in an embarrassing feat of self-deception, I pre-announced their license eight hours early on a KDE mailing list. That email was almost immediately picked up by Slashdotand other online news magazines, to my chagrin.

Troll Tech's new license is notable in that it takes advantage of a loophole in the Open Source Definition that allows patch files to be treated differently from other software. I would like to address this loophole in a future revision of the Open Source Definition, but the new text should not place Qt outside of Open Source.

At this writing, proponents of Open Source are increasing exponentially. The recent Open Source contributions of IBM and Ericsson have been in the headlines. Two Linux distributions, Yggdrasil and Debian, are distributing complete Linux system distributions, including many applications, that are entirely Open Source, and several others, including Red Hat, are very close. With the completion of the GNOME system, an Open Source GUI desktop OS capable of competing with Microsoft NT will have been realized.